He was only here because he was here every year and they liked to beat him - whether it be beating him up or beating him at drinking. He was only here because despite his aversion from Roland and the tendency to avoid the all-knowing types like Jamie and Alex, he was fundamentally, at his core, one of them, and he was expected to show up.
December was always an interesting time of the year. Pearl Harbour affected him in ways he didn't necessarily show, the two weeks he would spend vacationing in Hawaii after the commemoration were somewhat successful at reversing the effects, and then Christmas and New Year was gathering back with the group again, which, if anything, served as a greater reminder than any services he might have attended for Pearl Harbour.
He lingered around the shadows cast near the doorway but didn't make his presence known; he didn't need to with this lot in the vicinity. He had a beer and he wanted to finish it before everyone decided they would like to pick on Ryan now and start gravitating towards him.