Wittgenstein's Tractatus Logico-Philosophicus is always worth having a look at. Not everyone's cup of tea, but I greatly enjoyed it at around that age. Ed Th

Wittgenstein's Tractatus Logico-Philosophicus is always worth having a look at. Not everyone's cup of tea, but I greatly enjoyed it at around that age. Ed Thorp's autobiography "A man for all markets" is fun, in particular if you're interested in maths, gambling or finance.