"That's how you investigate. I know, it's what I used to do."

I’ve been playing Skyrim for a while, as has the known universe, and along the way you pick up quests like stray dogs pick up ticks.  You can’t avoid getting a quest.  Talk to a stranger and they’ll hand you tasks by the armful, leaving Skyrim so helpless you wonder how they get anything done without relying on mute foreigners to do their work for them.
Thankfully, all of these quests are listed on your Quest menu, and when I’m between big quests I’ll try to fill out the smaller ones that I have, apparently, completed incidentally without even realizing I’ve helped somebody: “Collect the bounty from Raerek,” or “Return to Talen-Jai.”
Then I saw “Go kill the chief at Dragon Bridge Overlook.”
So I went off to slaughter him.  I didn’t know why.  I had no recollection of anyone even asking me to kill these people, nor did I have any particular motivation to do so.  It was just on my list.  And as I stood among the dead bodies, I finally realized:

I had become Leonard Shelby.