In my opinion, David Foster Wallace gave the second best commencement speech after Steve Jobs. I encourage everyone to read this one. David talks about the importance of not only just thinking in general, but the importance of understanding what to think about.
An example that he talks about is when some one is hungry after a long day at work and there is no food in the fridge. Now they have to go to the grocery store. Once you finally arrive there and gather all of your items together to pay, you then need to get on a line, which you learn is a very long line. This frustration that you now feel is part of what David refers to as your "default setting" because this feeling just naturally occurs.