If you're already putting a clock on yourself ("ASAP") then you have made it harder. Somebody doing something for 12 hours/day is losing out on free time that

If you're already putting a clock on yourself ("ASAP") then you have made it harder. Somebody doing something for 12 hours/day is losing out on free time that makes life worthwhile. If you're Serena/Venus Williams, maybe giving up a normal life for mastery is worth it. But I imagine there are people that trained roughly the same number of hours and aren't operating at a level where they could comfortably tell people "I gave up years of my life to be able to do this". Most people involved in an activity day to day don't think of themselves as having mastered something. However, people on the outside of something who want to be on the inside may feel that if they can't demonstrate mastery, they won't be invited in.