This isn't about what necessarily makes you upset. Just a matter of what has caught you off guard. What doesn't make any sense? Stuff like that.
Sometimes I'll watch a funny video that has so much going on in it I get confused and then I'll say "What the f?" loud while laughing, and still confused. When I don't understand my tarot card readings I'll say "What the f are you saying...?"
What was the last thing that made you say it before you knew it? What makes you say it everytime it happens?