ok so i’m gonna try and cover everything, but my fiance originally came up with this theory while we were watching flowers for charlie, and we’ve since elaborated on it. it can be supported by a lot of canon despite the fact that there’s pretty much no way it actually is canon/true (although to be fair, parts of it are at canon, and i’ll even cite stuff, so idk).
so the theory goes: charlie is far more aware of himself and how he acts than other people give him credit for, and charlie is much more meta than he lets on, which isn’t that uncommon of a headcanon, but we kinda took it further.
so we know that charlie genuinely really loves to play characters (frank’s pretty woman, the gang reignites the rivalry, bums: making a mess all over the city, the gang solves the gas crisis, the gang makes lethal weapon 6, etc., etc.), but it’s sorta played in the show like he’s not that great at it. but we also know that charlie is better at manipulating others than he lets on (mac bangs dennis’ mom, charlie and dee find love, charlie has cancer). i’d also say that of the members of the gang, excluding frank, charlie is the most comfortable in his identity, and can be pretty self-aware in a way that the rest of the gang aren’t (charlie work).
so, flowers for charlie: charlie taking a placebo pill that he thinks will make him smarter, but really doesn’t, blah, blah, blah, you know the plot.
but if we look at it knowing that (a) charlie is more manipulative than he lets on and (b) charlie loves to play characters (and even has an interest in theater: the nightman cometh), then we can read not as charlie being tricked, but charlie knowing that he’s not actually “smarter” but if he just pretends like he thinks he is, then he gets a whole audience (scientists, his friends, anyone who comes to the talk in the last scene) to watch him play the genius (”is he doing an accent?”), and probably has a great time doing it.
so ok, if we look at lethal weapon 6 next, then, he plays the weird danish twin’s twin, and the captain (i don’t remember if he plays anyone else tbh). anyway so we could look at this and say it disproves the theory because he does such a bad job as the captain, but honestly watching it, the discrepancy between him as the captain and him as the danish twin is pretty extreme, and here’s why imo: first, he doesn’t like being told what to do (the gang gets analyzed), so even though he wants to be in the movie, the captain probably isn’t the character he’d most enjoy playing (no accent, no action), second, the danish twin has no lines.
learning his lines for playing the captain must have been hard, because someone would have had to read them to him and teach him and that would be annoying for charlie most likely, especially because of his auditory processing issues (the gang recycles their trash), so he’s not having fun playing the captain. on the other hand, he (presumably, unless mac and dennis had a really clear vision of what the danish twins act like) came up with mannerisms and a whole personality for the danish twin despite not having any actual lines.
i already mentioned charlie and dee find love, but i always saw that ep as very intentionally showing that charlie isn’t the “good one” of the group, and he can be just as downright cruel as everyone else. not only that, but he’s acting the whole episode, and convinces everyone that he really likes ruby. if he’s capable of something that requires so much subtly and dedication (even… apparently having sex with her despite being sex repulsed), it’s not that much of a stretch to say that he could be duping anyone/everyone at any time.
anyway uh i probably forgot stuff and there’s almost certainly gonna be holes in this theory but like i said it’s a fun way to read charlie’s character, and it makes watching charlie really fun bc you get to question how much he’s acting at any given moment. obviously he’s not Totally self aware, there are definitely things, like his infatuation with the waitress, that he’s not exactly self aware about the fact that it’s a hopeless cause, but i also kinda think that he lacks self awareness/avoids facing reality very intentionally at least some of the time (a very sunny christmas, he decides not to believe what mac’s telling him/what he remembers about his mom). but in essence that’s the theory :-) hope that wasn’t too boring to read!