A few of my friends have done startups, and I have noticed something really important about the "why me" question: it seems to be THE determiner of how much you can actually capture from starting up a company. The questions of product/market fit and timing determine whether a company in the space ought to exist. The "why me" question tells you how much your startup can capture independent of the money and work of other people, and how much of that reward you will get.

Since then, I started up a company that I think I am uniquely qualified to run, but we'll see if we get there.