In quantum mechanics, we have to abandon the idea that particles have definite properties before measurement.

I was working at a financial firm in New York City with a bunch of very smart people， and I had a brilliant boss that I much admired. I went to my boss and told him I wanted to start a company selling books on the Internet. He took me on a long walk in Central Park， listened carefully to me， and finally said， "That sounds like a really good idea， but it would be an even better idea for someone who didn't already have a good job." That logic made some sense to me， and he convinced me to think about it for 48 hours before making a final decision. Seen in that light， it really was a difficult choice， but ultimately， I decided I had to give it a shot. I didn't think I'd regret trying and failing. And I suspected I would always be haunted by a decision to not try at all. After much consideration， I took the less safe path to follow my passion， and I'm proud of that choice.