What am I doing?

Finally responding to this post on LessWrong.

Why am I doing it?

I don't quite feel tired yet, and I don't know which book to pick up for pre-sleep reading: Wicked, so I have some context when I see the musical with my girlfriend in June. The Ancestor's Tale because I find evolution extremely interesting, and there's the off chance that it will be relevant to my future research (and I'm obligated to read it since it was a gift). Or The Theory of Moral Sentiments because I find the moral sense theorist to be interesting precursors to Eliezer and others in metaethics, and I still haven't read it yet, and for Vassarian reasons.

Hmm, Which one should I start reading?