It depends on what you consider "fun". What might be fun for one person might be the total opposite for another.
Like a roller coaster. For some unfathomable reason I fail to see the fun in being terrified and nauseated.
Or skydiving. One of my recent favorite sayings is "If at first you don't succeed, don't go skydiving".
Or, for a less extreme version, going to a party where there are a lot of people and they just sit around talking to each other and not to me, and the food and music isn't good enough to be a decent distraction.
I will be going to buy my groceries soon. Here's hoping it will be crowded, noisy and the line-ups long and slow-moving, with lots of whiny and screeching little kids, and my shopping cart's wheels don't all move in the same direction, and my trying to choose from all those products without going over my budget will be impossible.