What is so funny about this?!

Rating: 5/10 (15 February 2001)

I see review after review telling me that this movie is hilarious -- "the funniest movie ever," etc. And yet, I found it only mildly amusing. What am I missing? Okay, (semi-"Spoilers" ahead!) we already know the plot: 2 guys escape the mob by joining a women's band and dressing as women. In the meantime, they interact with Sugar (Marilyn Monroe) and lots of silly capers follow. They run into the mob again at the end, but get away because everybody involved is so stupid. At the end, we get this amazingly surprising revelation, "but I'm a man!" Capped off by a very memorable ending, "Nobody's perfect!" All these reviews say that this has them rolling around in laughter. All it evoked from me was a wry chuckle, about the most laughter I got out of this movie.
What is supposed to be funny about this? What is so "sensual" from Marilyn Monroe's performance? Having not yet become a prolific movie-watcher, this is the only movie I've seen her in (primarily because it ranks so highly on the AFI 100 and IMDb charts and I wanted to find out what made it so good), and I can't tell if she really is the '50s equivalent of Pamela Lee, or is supposed to act the part of a bimbo. The radiant sexuality she was supposed to exude is marred by the plain fact that she was a bit chunky. At least Pamela has the body!
Which leads me to wonder: were '50s audiences this deprived? That was my assumption, but I see loads of reviews from contemporary viewers saying that they found it hilarious -- which leaves me baffled. Just *what* was so funny? Almost each and every odd moment that is supposed to evoke humor only prompts me to say, "This is stupid/moronic/silly." What perhaps makes this so *un*funny for me is the utter lack of realism. Two dolts dress up in drag and *nobody* sees how blatantly obvious it is that they aren't women? But wait -- that nobody sees this is supposed to be what's so funny. . . right? How? I'm dumbfounded, finding nary an explanation. Someone want to clue this philistinic reviewer in?
At this point, I must add that I am extremely disappointed in the quality of the reviews here. I came here to find out *what* it was that I had missed, and I got basically *nothing* of useful content. I mean, there must be *some* good reason that this is #14 on the AFI list, right? Did it revolutionize the genre or the industry in the way that the mildly entertaining "Citizen Kane" did? How? I would have hoped and expected that the reviewers here, presumably of more intelligence and sophistication than the movie-going public at large that opts for "There's Something About Mary," would have *something* useful to say about *what* makes this movie funny. "Jack Lemmon was great in drag" tells me *nothing*. That Jack Lemmon dressed in drag tells me *nothing*.
I'll refrain from passing judgment in the form of numbers of stars or #/10, pending some *useful* explanation for this unexplained phenomenon. I might mention that this is the only movie in the top 20 on the AFI list about which I am thoroughly baffled for its being there.
For what it's worth, some recent-year movies I *did* find enjoyably funny include "Election," "The Big Lebowski," and "Fight Club." (Now, Tyler Derden telling us that blowing up credit card company buildings will help achieve "economic equilibrium" -- now *that's* funny!)