how many is "many"? Surely everyone I know has more than 3 or 4 things going on in their lives. What is being "committed"? Sacrifice? How much time is spent "doing" instead of "thinking"? How much time learning to be the Jack of all Trades in that one interest? Hmm, I guess this is one reason why I don't just come to Steve's website for personal development. I check out others and their ideas.
I find many people kid themselves into thinking they have too many interests, but they're not even close to being any good at them. I use to think I was good at dancing, until I joined a dancing battle. My level of commitment was surely not as high as others. Yes, I was more skilled than my friends, but knowing there were hundreds of people more skilled than I was killed my confidence. Kidding myself into thinking I was good got me thinking about everything else I thought I was good at and ultimately leading to personal development. Well, that was 3 or 4 years ago during my young days. It's all about knowing where you stand and knowing where you want to stand.