I have had a few landings over the years where things did not go as smoothly as one would hope for. The two that were closest to an incident were one where we had a lot of difficulty braking and nearly veered off the side of the runway (from row 1 I could hear multiple alarms going off in the cockpit) and the other where we floated above a 6000' runway for too long and the pilot made the decision to put the a/c on the ground rather than do a go around (for a little perspective, it was the hardest landing the non-rev pilot next to me had ever experienced). Neither one, did I feel that we safely arrived when the wheels touched down. Even if you are and occasional flier, you kind of get the sense when things are off due to that fight or flight instinct we all have.