Buying books for myself in December

It is poor form to buy yourself books in December, at least for me. If people are going to give me gifts they generally opt for books, as they know I will like that. I therefore usually avoid buying any in December. Today I sold some books at Powell's and bought The Darkness that Comes Before and the Plot Against America. I could say something smarmy like I needed to do something nice for myself or whatever, but really I was just feeling greedy.