I believe there are three factors to consider: - what you are trying to learn - your ability to learn things on that particular area - how you measure [famil

I believe there are three factors to consider: - what you are trying to learn - your ability to learn things on that particular area - how you measure [familiar/proficient/good/expert/impress people] The time it takes to get to those levels can vary a lot and you can't really use the same rule for all. It is almost like saying that if a group of people spent 5 years in college together and by the end of it all of them have the same level of expertise. We all know it doesn't work this way. I think these X-hour rules are flawed unless they are very specific on the three factors I mentioned. The 10k hours probably works simply because it is a lot of time... not because everybody learns the same way. EDIT: formatting