Have you ever had an experience so bizarre and singular that you barely believe it yourself? Telling those stories can be strange, since you're fully aware of how far-fetched they sound, but the most inexplicable experiences make for the best happy hour anecdotes.
Plus, in the best case scenarios, sharing your "hard to believe" story might open the door for someone else to share their equally bonkers experiences.
I knocked a cup of coffee off my counter and caught it and no coffee spilled out of it.
One time when I was a teenager I was playing pool with friends. The pizza arrived or whatever and I took one last shot just as everyone was leaving and sank like five balls. It was the single best move I have ever made in any game I have ever played, but no one saw it and there was no way to take credit for it without sounding like a liar.