A lot of people treat choosing their cofounder with even less importance than they put on hiring. Don't do this.

The hard part is that this is a very fine line. There's right on one side of it, and crazy on the other.

The most common post YC failure case for the companies we fund, is they're incredibly focussed during YC on their company... and after they start doing a lot of other things. They advise companies, they go to conferences, whatever.

When it comes to starting startups, in many ways, it's easier to start a hard startup than an easy startup.

No matter what you choose, build stuff and be around smart people.

You want an idea that not many other people are working on, and it's okay if it doesn't sound big at first.

... you can think about that for everyone you hire: will I bet the future of this company on this single hire? And that's a tough bar.