I recently went to Florida with a carry-on and as I boarded was told there was no more overhead bin room and that I'd have to check my bag. Ok, no big deal. Got to Orlando and my bag wasn't there. Now, someone took my bag thinking it was theirs, and while Florida in 30-hour-old underwear, athletic pants, and a t-shirt wasn't awesome and I got my bag back, had I gotten on the plane earlier I wouldn't have had to deal with that issue. I never check a bag and so I get on as early as possible so the above doesn't happen again.