The motto of Brian McCormick's excellent basketball newsletter is "Practice in Proportion to your Aspirations".
What percentage of your work time do you spend practicing your craft?
I once attended a Microsoft Code Camp and asked this question of approximately a dozen speakers. The answers ranged from 15% to over 30%. Jesse Liberty was the speaker who spent over 30% of his time learning.
I find it informative that one of the best known writers in the C# community spends so much time learning. Not surprisingly, he knows more than most programmers (and authors) and is able to make an excellent income from his books.
I find it comical that at the most dysfunctional organizations, the ones that would benefit the most from learning, virtually no emphasis is placed on getting better. The notion is that more works gets done by doing work instead of learning how to work better.