To finish the moment, to find the journey’s end in every step of the road, to live the greatest number of good hours, is wisdom. – Ralph Waldo Emerson
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. – Stephen Hawking