Back in Time: My Advice for the 21 Year-Old Me

The problem with time travel is paradox. If you go back in time and tell your younger self to change things, -this- you doesn't exist any more.

So you tell that younger you to just pick an idea and go with it, instead of waiting for the perfect idea. You know, the one that started you on the road to success. He runs with it, fails, and the rest of his life follows from the lessons he learned from that failure. Perhaps that lesson is that he's not fit to be an entrepreneur, and he goes on to be a wage-slave the rest of his life.

Don't mess with success. It's dangerous enough to try to correct failure, but changing things in the chain that led to your success is incredibly foolhardy.

My advice to 21 year old me would be easy: don't blow off that Microsoft interview in 1982 because you don't want to move to the Seattle area.