Lisp is worth learning for the profound enlightenment experience you will have when you finally get it; that experience will make you a better programmer for the rest of your days, even if you never actually use Lisp itself a lot.
I think it's very important to have a feedback loop, where you're constantly thinking about what you've done and how you could be doing it better.
"A wordless book speaks in a universal language."
The spread of liberal democracy and the integration of the world economy have created a situation in which the major powers are no longer willing to risk war with one another.