If you get asked to do something that would take place down the road (say you get asked to speak at a conference that's a year away) and you wouldn't want to do it if it were taking place next week, then don't do it. This advice has helped me evaluate the opportunities that I truly want to dedicate my time to and those that I don't.
Luis von AhnI co-founded Duolingo with the mission of bringing free language education to the world.
Luis von AhnTogether with my advisor, Manuel Blum, I co-invented CAPTCHAs, or computer-generated tests that humans are routinely able to pass but that computers have not mastered (they are the squiggly computer letters that are prevalent across the web).
Luis von Ahn