Fun... not really. At this point I am not sure what my H would consider fun. He is so self conscious all the time, it is hard to have fun with him because he never lets loose. I embarrass him.
That one hits close to home. I used to be a stick in the mud too. I was a pretty fun/entertaining guy 20 years ago, but I lost him as the stresses of life overwhelmed me (working hard to get him back!).
That said, maybe it's a topic of discussion you can have with H. There's a section in Gottman's book where he wants you to delve into each other, to get to know each other better. Maybe use this in conjunction with the "fun" topic and see where it goes.
I view it the same as DB and trying to save your M. You can't always be reading books and trying to improve yourself....you'll get overloaded and go crazy. You have to mix some GAL in there to keep it balanced.