I seldom think about my limitations, and they never make me sad. Perhaps there is just a touch of yearning at times but it is vague, like a breeze among flowers.
As soon as we started programming, we found out to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs.