Full credit to the guy for managing to play 40 sessions like that, though.

Characters rarely, if ever, turn out exactly as they're envisioned- that's part of the beauty of them. As long as you play someone that works well with the team and keeps the party together so everyone can enjoy the adventure, then you've done well. Sure, this guy probably turned out to just feel like a haunted, cold person travelling with the party for no clear reason, but that can still contribute to having a solid party dynamic.