This phrase occurred to me the other day. I shouldn't sell myself short. I don't know the full extent of what that means, even, but immediately when I made that decision a professional opportunity presented itself to me. A coincidence.
A non-professional example: thinking that I am not good at piano playing is an artificial constraint on getting better. Not selling myself short would mean getting as good as I can realistically--a lot better than I am now.
I wrote in one of my false Bronk poem that we didn't really have a choice about being modest. Anybody should be able to see his or own defects, more or less, as well as a kind of cosmic insignificance. The only choice aside from modesty is a kind of foolishness, then. Within this essentially modest framework, though, there are certain gifts that should not be squandered. It is not arrogant to know one can excel in a certain area.