I think this is precisely right. There are many more folks who could be claimed experts, who have not become wealthy like Buffet, or Gates. I treat the 10000-ho

I think this is precisely right. There are many more folks who could be claimed experts, who have not become wealthy like Buffet, or Gates. I treat the 10000-hours/10year milestone as more of an indicator of when you should have sufficiently absorbed a great deal of the subject matter -- indeed it would be hard not to spend so much time and not become intimately familiar with the thing. Of course, those 10000 hours need to be spent practicing and learning, not just screwing around.