It is no good getting furious if you get stuck. What I do is keep thinking about the problem but work on something else. Sometimes it is years before I see the way forward. In the case of information loss and black holes, it was 29 years.
“Do I think I was put here on earth to be a journalist and to seek truth? No, I don't.”
“Anger is a killing thing: it kills the man who angers, for each rage leaves him less than he had been before - it takes something from him.”