The buy up highly educated people in their 20's because they're cheap and eager to work. In fact, they're cheaper than most people when you do an hourly analysis (probably cheaper than cleaners).

BUT... the simple fact is, they also know they burn out by their 30's. Life takes over. The doubt. What am I doing with my life? Why don't I have a family? Maybe I missed out on other things my friends were doing?

By that stage, they no longer care about you because they've got a new batch of cheap 20's burning the midnight oil.

However, the good news is that they noticed that there's a reversal when people reach their 40's. They've got experience in life and business. They're no longer in doubt mode.

Ironically, these organizations have standard pitches to sell the career delusion. "People are our greatest assets" and similar rhetoric. The reality is ... THE DO NOT GIVE A CRAP ABOUT YOUR CAREER. Careers do NOT exist. It's like selling women the idea of being a "homemaker" in the 1950's.

I have noticed that people are more likely to be successful in their 30's and 40's (read some evidence that suggested that too but can't remember the reference). People getting rich in their 20's is an aberration.

Neuroplasticity (http://en.wikipedia.org/wiki/The_Brain_That_Changes_Itself) also suggests that we never stop learning, so I have to disagree with point 3 "Your brain finishes forming in your 20's." Dribble! That's like the rhetoric about careers. People just get lazy.

What people have going for them in their 20's is no commitment and all the time in the world. But no experience which can also be a disadvantage. If you can recreate "no commitment" in your 30's-40's (20's + real experience), then you should excel because your ideas are more mature and hopefully clearer!

You're more likely to be successful as an actor in your 30's for the same reasons!

But I don't think many people would deny that one's 20's are a key decade. In fact, if I had to pick a most important decade, that would be it. In your 20's, you're expected to start a career, and to do something valuable for society. You're going to meet the people who, 20 years later, will be willing to work with you because "I've known him for decades." 20-somethings have more energy than older people, but more direction than younger people.

Nobody seriously thinks people "suddenly" can't build cool things at a particular age. But I know very few people who would think that someone's intellectual output or energy keeps growing past their 20's. Of course, very few people expect a 25-year-old to be as wise or well-connected as a 45-year-old; if I were betting on who would start a better law firm or hedge fund, I'd bet on the older guy.

The twenties are for launching, while the thirties are for building what you launched.

The main point is to recognize the state of your brain at a given age and its resulting effects:

The trick is simply to take advantage of each power in the season it is given

That is applicable regardless of chronological age.

This is IMO impossible without experimentation and doing stupid stuff during the 20s.

I just turned 35 and only starting out on the best work of my life in the shape of offering something of value except for just my time at work prior.

Edit: There is an important balance to keep the enthusiasm of your 20s for a long time, and keeping a little wisdom of recognizing those situations that want to take advantage of a few years of your life in your 30s and being a little more conscious about it.

Graduate: Say age 22. You have ~20 years to make most of what you're going to make.

I'm not saying it's impossible to work after 40, not at all. I'm just trying to tell anyone who will listen that is is harder and even with full employment in tech, it is still hard to make the kinds of moves I made in my 30s, reinvent myself, and generally do the cool things I want to do.

I'm 31. I'm working on a project with a low chance of success, but it will change the world if it does succeed. (Granted, it's done as part of a large organization, but I also haven't ruled out startups if the large organization ceases to be a good place to innovate, and now I have the financial wherewithal to do so.) The main difference now vs. when I founded a startup at 26 is that now I know the chance of success is low, but I don't care. Because I've learned that just because I don't see a solution immediately doesn't mean that one doesn't exist. And that this is what I want to do, my basic needs are taken care of, and so it really doesn't matter if it doesn't work, I'll be happier having tried. And that other things that would otherwise be distractions are only distractions to the extent that I let them be so - my friends will be there when I want to invite them out, my bills are on auto-pay, and I have the right to say "no" to other projects at work.

Your 20s are a time when you outgrow most of your insecurities and learn who you are and what you really care about. If accomplishing great things or founding a startup or just plain innovating is one of them, then you can do that for the rest of your life. If you're just doing it because the Internet says you should, then you won't be any happier having finished it off in your 20s than if you spent that time learning about yourself.

Maybe it's not about "too late", but I think it gets a lot harder to change yourself as you get older. If you're on a good track, you're more likely to stay on a good track; the same for the less-than-good tracks. Creative people will continue to gain creative competence, which is why most peak in their 50s-- it takes a long time to get good-- but I think that someone who voluntarily gives his creativity up, in order to become a social climber, if he hasn't reclaimed it by middle age, probably won't.

There are a lot of people who go into banking and consulting expecting to cash out, retire young, and become novelists or philosophers. Very few of those actually do it.

You should take your 20's seriously... because it's the only time in your life that you aren't encumbered by building a career, having kids, etc.

So you should take your 20's to do the things that you won't be able to do later. Work as a bartender, play in a band, travel the world on the cheap, teach English abroad, date the kind of people you wouldn't marry. You don't have serious responsibilities, so take advantage of that while you can.

Don't waste your 20's "building a career". You've got your 30's and 40's and 50's to do that. Don't be in a rush to have kids too soon.

Obviously, don't throw your 20's away. But spend them doing life-experience-focused things, not career- or family-focused.

And this gets at the author's third point: "Your brain finishes forming in your 20's". If that's even true (although I doubt it), then you'd better get in all those varied life experiences sooner rather than later. Learn a second language, learn to cook, learn to play music.

Don't waste your 20's on grinding away at traditionally career-oriented stuff. That part of your brain is probably already fine. Your 20's is the time to look for diversity in your life, not to focus narrowly on any particular part. You've got all the decades afterward to work on narrow refinement and career progression...

I took some risks and enjoyed my 20s and early 30s immensely, but also played it pretty safe. I would advise my younger self to take more risks, specifically around creating products.

A lot of popular blogs (eg. Marc Andreesen's) divide up your career into phases, where you optimize for different things in each phase. Your 20s is usually the "development" phase, where people hire you for what you can do in the future. Your 30s is the "harvest" phase, where people hire or acquire you (at substantially increased rates) for what you've done in the past. You want to optimize for skills & experience during the development phase, because otherwise, there's no reason for anyone to hire you during the harvest phase.

Granted life is pretty good now if you're a recent graduate of a good school. You almost have your pick of jobs. But when was that not the case?

It's true that you tend to have less commitments in your 20s. You should take advantage of that. Most people in their 20s still spend their money on crap however (cars, ski trips, eating/drinking out, etc). While that's all fine they'll wake up after 10 years and find they have nothing.

What tends to happen as you reach your 30s is you have increasingly financial commitments. You might have bought or want to buy a house. You may well be married. You might have children. All of these take your time as well as make you more risk-averse both from a stability point of view as well as having a higher minimum salary that you can pay your bills on.

But if there's one thing I've learned over the years is that most of these expenses are, well, crap. Raising children is expensive but it's also way more expensie than it needs to be, in similar ways to being single in your 20s is way more expensive than it needs to be.

That doesn't mean you have to stay at home, never buy anything and never do anything. It just means being smart about how you spend and allocate what money you do make.

I could lose my job tomorrow and not need to work for another 12 months, possibly two years if I push it. That's a deliberate choice I've made.

It also means that if I want to bootstrap a startup I can.

In my experience, most people in their 40s either:

- don't have an interest in something so risky;

- have let themselves and their knowledge get out of date;

- have priorities that preclude anything but a 9-5 job; and/or

- don't have the financial freedom to take risks.

While you may not have the energy you did 20 years ago, experience counts for a lot. We're lucky in that we work in an industry where you only need:

- working hands;

- working vision (and a very low level of vision too as I can personally attest to); and

- a working mind.

I see no reason why you can't work as a programmer until you go senile, go (literally) blind, are quadriplegic or die.

People who can code and can get shit done are (and will probably be for the foreseeable future) extremely valuable... regardless of age (IMHO). I see so many people who work in this business who actually can't code, it's astonishing.

Some might write you off if you're not a twenty-something MIT or Stanford graduate. But if you keep up to date and are willing to take risks, I see no barriers to a continued productive existence other than those you create.