Conversation so far:
When did Alan White join Oasis?
CANNOTANSWER.
Why did he leave the band?
Noel Gallagher alluded to White's personal problems: "He's a ******* great guy, and he's one of the best drummers I've ever met in my life, but his personal life.

Question: What about his personal life?
Self-contained rewrite: What about Alan White's personal life?