Other posters have commented about the validity of the 10k hours rule. I actually think even more radically - career, or success in general, is not necessarily

Other posters have commented about the validity of the 10k hours rule. I actually think even more radically - career, or success in general, is not necessarily a matter of mastery, and thinking in terms of technical skills, may lead to failure, because the requirements for success may be other ones. In particular, successfully founding a company may require many qualities (and acts) that have nothing to do with technical skills, rather, with human ones. I'm not familiar with your boss, but it's possible that they just found a market need, and dedicated themselves to solving it, even with mediocre skills, but with the right human skillset (creative ideas, understanding of the market, orientation to get things done, effectively communicating, and a myriad of other things). There are certain fields where technical accomplishments is the main drive (Doom ;)), but in such cases, the answer whether that's possible or not is very obvious. I stress: it may seem paradoxical, but a strictly technical vision can be counterproductive even in a technical field.