[marcosdumay]

It is important to point out that on his speech (and the book) he tells people to work on important problems (always on the plural), and that he never say not to work on non-important ones.

In fact, I remember the book having a very clear assumption that you can't work on important things all the time anyway. But well, there has been some time since I've read it. But it is a very sensible and nuanced advice for highly ambitious people.