don't feel like you're doomed to fail if you're not sure on day 1 that you want to be running a public company. Not being sure of that is if anything… - Paul Graham

Users are a double-edged sword. They can help you improve your language, but they can also deter you from improving. So choose your users carefully, and be slow to grow their number. Having users is like optimization: the wise course is to delay it.

It’s hard to predict what life will be like in a hundred years. There are only a few things we can say with certainty. We know that everyone will drive flying cars, that zoning laws will be relaxed to allow buildings hundreds of stories tall, that it will be dark most of the time, and that women will all be trained in the martial arts. Here I want to zoom in on one detail of this picture. What kind of programming language will they use to write the software controlling those flying cars?

Medicines are very unusual among technologies in that faith in them preceded efficacy.