Insane.
EDIT: It's really crazy. I didn't know him at all, but his username and avatar are recognisable to me. It's not so much a sense of loss to me, I have lost a fellow poster and potential friend but I can't really claim to have lost someone that I've never known as a friend. Instead I'm left with an unsettling feeling, almost like the world has changed, and it will never been the same again. The frightening thing is I wouldn't have even known the world had changed if it wasn't for this thread. Carsick will never post again, and I would have continued my activity, not noticing the posts that, while not missing could have been there and changed entire threads.
Forums offer very remote connections to a large number of people, and I suspect this is far from the only time a poster I've interacted with has died, but it is the first time I've known that it has happened.
I'm sure he was a good bloke, I don't want to sound disingenuous so I'll let the people who did know him make the tributes, the above is more self-reflection really.