Because if life isn't fun at least some times, what in the doggone world is the point? Let Charlie Brown's life belong to Charlie Brown. (Do young people even know who Charlie Brown is anymore?) If a cloud floats over your head, someone is always pulling the football out from under you, or your dog's world looks better than yours does, then change something. Change can be fun. And follow I’M 49 GOING ON 50 MENTORING TIP #18, if necessary.
This is your life. As far as I know you only get one of them. Carrying regrets and looking back at lost (and irretrievable) time becomes more painful than you can imagine as you get older. Don't condemn yourself to that.
Laugh during church, dance at a funeral, spin around in a circle for no apparent reason, do a cartwheel, take that painting class you've always wanted to take, go out with friends on a Monday night, sit by a waterfall, spin around on your chair in your cubicle (but don't unscrew it), hang upside down from your sofa, go to the movies at lunchtime, wear clothes that don't match, swing on the swing-set (make sure you have your FBI clearances first or it could get ugly -- and fast!), and learn to laugh at yourself.