Well, as you point out, he wasn't thinking very straight at the time. He may have "regained the ability to function on a basic level" when he left New Avalon, but he was looking for solitude, that "Exile frame of mind" as it's been referred to elsewhere. (Interesting, that he often looks for comfort by looking back to the darkest time of his life, but there it is.)

Perhaps when he realized that he should have taken Wolfgang with him, that became the moment when his thoughts began to once again turn outward, and back to all the other things that still mattered to him?