Another phrase we can all agree to stop saying: "He just loves to have fun." This is a phrase I've often heard people use to describe others and it drives me crazy. At the end of the day (winky frowny face), this may be the most redundant sentence ever. I can actually use science to prove this. Enter proof by contradiction.
Let's imagine for a second that someone hates having fun. In such a case, they would seek out activities that most of us consider not fun: root canals, filing taxes, watching The Tyra Banks Show. So our subject wakes up one day, picks out his desired activities and then jumps into the dentist chair, flips Tyra on the tube and goes to town. In doing so, he's doing what he wants to do and enjoying himself. Ergo, having fun. Unless someone is doing something someone else has forced them to do at all times, they have to choose something to do ... and no one's going to choose something to do that they hate ... and in the process you'll be having fun.
I think we can now officially strike "likes to have fun" from our collective lexicon. It's science.