Lisp is better at enhancing your thinking abilities than Python, though less practical and less desired by the marketplace.
Structure and Interpretation of Computer Programs is a classic programming book that is widely considered to enhance one's thinking abilities. It uses a dialect of Lisp, Scheme.
SICP is freely available online: http://mitpress.mit.edu/sicp/
Some research says that lurkers make up over 90% of online groups. I suspect that Less Wrong has an even higher percentage of lurkers than other online communities.
Please post a comment in this thread saying "Hi." You can say more if you want, but just posting "Hi" is good for a guaranteed free point of karma.
Also see the introduction thread.