So many times, as a smart and capable person, I can see the light at the end of the tunnel in a new endeavor. Even when I don't really see it I trust it's there if I can grasp even a little. But with some things you just feel lost, and that's very difficult for smart people.
This is so different from learning a game like backgammon. One summer in my mid-teens, a friend and I played many times daily over a summer. I've rarely played since, but the strategy is easy enough for a smart person that I can hold my own against anyone except world class players. That's a bit to one extreme, but it's closer to the average experience of a smart developer.
Finding things that I just can't grok after a few minutes of thinking about them (and there are many) has made me more accepting of my limits, and raised my awareness that some things take a mental shift and/or really are complex.