No fun because it physically hurts to do so or because it doesn’t feel good emotionally anymore?
I can no longer enjoy a lot of physical activities that I used to enjoy like chasing someone while screaming at them because I simply don’t have enough energy to spare. I can still see how they are fun, but I just don’t enjoy them as an adult.
Things that I used to enjoy but now just make me cringe or disgusted are some genuinely harmful things like creative ways to cause a mess and shift the blame to an innocent person. I’m glad I no longer see enjoyment in those things.