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.
Yes there's such a thing as luck in trial law but it only comes at 3 o'clock in the morning. You'll still find me in the library looking for luck at 3 o'clock in the morning.
