How to succeed: pick the right thing to do (this is critical and usually ignored), focus, believe in yourself (especially when others tell you it's not going to work), develop personal connections with people that will help you, learn to identify talented people, and work hard. It's hard to identify what to work on because original thought is hard.

Work very hard—a surprising number of people will be offended that you choose to work hard—but not so hard that the rest of your life passes you by. Aim to be the best in the world at whatever you do professionally. Even if you miss, you'll probably end up in a pretty good place.

In almost all ways, having enough money so that you don't stress about paying rent does more to change your wellbeing than having enough money to buy your own jet. Money can buy freedom, and that's a big deal.

Go out of your way to be around smart, interesting, ambitious people. Try to spend time with people who are either among the best in the world at what they do or extremely promising but totally unknown. It really is true that you become an average of the people you spend the most time with.

Minimize your own cognitive load from distracting things that don't really matter. It's hard to overstate how important this is, and how bad most people are at it. Develop very strong ways to avoid letting crap you don't like doing pile up and take your mental cycles.

Don't worry so much. Things in life are rarely as risky as they seem. Most people are too risk-averse, and so most advice is biased too much towards conservative paths.

Existential angst is part of life. It seems to particularly affect smart, ambitious people. One of the reasons some people work so hard is so they don't have to spend too much time thinking about this.

If you think you're going to regret not doing something, you should probably do it. Regret is the worst, and most people regret far more things they didn't do than things they did do. When in doubt, kiss the boy/girl.