[ajarmst]

The numbers are arbitrary. My primary point is that many important skills cannot be learned without the requisite experience. Individual experiences, talents and interests vary. Perhaps adjust my crude analogy to note that your very good manager at 28 would probably agree that she wasn't very good at it when she first left school or for the first few years of her career, and that her skill at working with other people was learned primarily from working with other people, not self-study, instruction, or other process that allowed for much compression of the time it takes. Those who excel early usually have done so because they started earlier and sought more opportunities for the necessary experience. I suspect if you broke it down to hours, you'd find a similar number, just applied at a rate of 20 hours a week instead of 10.