A couple people have mentioned reading fiction. What I should have
mentioned is that I do enjoy reading and contemplating philosophy
when it is an integral part of a good story.
In fact, I think that I developed a lot of my personal philosophy
from an amalgam of Heinlein, Doc Smith, Star Trek, Gordy Dickson,
etc. -- tolerance, individual liberty (freedom *plus* responsibility),
thinking for yourself, honesty, perseverance ...
Mostly read when I was a child or early teen.
Some days I think the best thing we could do to help this country
would be to buy a copy of _Citizen of the Galaxy_ for every
middle-schooler.