The day I want to travel - New Year's Eve - there aren't any direct trains from London, apparently, so you have to change at Reading. Given I'm going to be carrying a large proportion of my stuff for next term, that, combined with NYE Underground, is not something I want to do.

The other option, apparently, which actually takes a few minutes less, is get a train direct up to Derby then a train straight down to Oxford. I refuse to do that on principle.