No one truly enjoys being an adult all of the time. Many times there is not much fun to be experienced when being an adult, but don't you suppose that maybe God gives us those simple moments in order to revive our child-like faith and joy? Don't you suppose He loves us enough to give us the gentle escapes from adulthood? So if you can believe that, it should not be any harder to let your hair down and laugh from deep in your belly or jump for joy the next time something makes you truly happy.
Have a wonderful day, all! :)