Let me think, Adventure Time started airing while I was still in college, right around the time where I had finally had enough of anime and /a/. Ended up on /co/ when I started getting back into cartoons and hit upon Adventure Time.
The AT drawthreads were the first threads on /co/ I had posted in.
I stuck with the show until the episode Furniture and Meat. I don't know why, but that episode just rubbed me all the wrong ways. I got back into the show later and caught up through stakes, then the show was on hiatus so often I thought it wasn't airing anymore.
I got into it again right after Islands and got slapped with another hiatus and forgot about the show again for a while.
Then I caught up through Elementals miniseries to the episode before the finale before the finale aired so I'd be up to speed.
I think the show would work a lot better even with all the inconsistencies if the schedule didn't have those massive hiatuses.
I'm not sure how hard the show ending has hit me, but I sure as hell remember the highs with enough fondness that I don't really recall the lows despite knowing where they are and what they are.