As I grow older, I find fewer things funny. Curiously elephant jokes still work on me. The steady rise of my chuckle-or-cringe threshold hasn’t been a monotonic progression from childish to sophisticated. Things are more complex.
One reason, I suppose, is that over an adult decade-and-half, I’ve experienced at least one complete cycle of innovation in humor (the rise and fall of Seinfeld-Leno style observational humor) and consumed a critical quantity of at least three major kinds of humor (Indian, British and American, in order of influence on me). The result is that these days I can often place a joke or gag in space and time and explain it away quickly enough to kill the chuckle before it is born. Sometimes before the punchline.