People are considered smart because they have an advanced degree, an impressive vocabulary, or are well-read. But how we apply what we know is more important than what we actually know.
When I read a book, attend a seminar, pay attention to people wiser than me, or make a mistake, I always look for the take-aways and biggest learnings. The best way to do this is to ask: how will I use this?
Learning but not making use of it is roughly the same as not learning in the first place.