The transcript of Richard Hamming’s 1986 conference You and Your Research is very much worth reading, if nothing else for the following quote:
And I started asking, “What are the important problems of your field?” And after a week or so, “What important problems are you working on?” And after some more time I came in one day and said, “If what you are doing is not important, and if you don’t think it is going to lead to something important, why are you at Bell Labs working on it?”
Paul Graham evaluates it in his essay Good and Bad Procrastination, where he says:
Perhaps not everyone can make an equally dramatic mark on the world; I don’t know; but whatever your capacities, there are projects that stretch them. So Hamming’s exercise can be generalized to:
What’s the best thing you could be working on, and why aren’t you?
PS: Coincidentally I found both links on an older post on Marginal Revolution, which was posted exactly a year ago.