Lloyd could be a Jerkass Woobie - he travels across the country nearly getting killed/raped in the process just to give his dream girl her briefcase, his best friend steals her from him (so he thinks), and finally learns that she's already married. And to top it off he's simply too dumb and/or crazy to realize that she's completely out of his league anyway.
Which one's "Dumb" and which one's "Dumber"? Lloyd for having even less sense than Harry exhibits, or Harry for letting Lloyd fast-talk him so often?
And You Thought It Would Fail: Bennett Yellin's initial draft of the script was apparently so disjointed that it had gained a negative reputation among film investors. After the script was re-written, it was pitched to producers under the fake title A Power Tool Is Not a Toy, in order to get them to even read it.
Fanon Discontinuity: Most fans of the original film would prefer to pretend that the prequel never happened.
First Installment Wins: The original Dumb and Dumber is one of the most popular and beloved comedy movies of the 1990's. By contrast, the prequel, Dumb and Dumberer, is often regarded as one of the worst comedies of the 2000's, while Dumb and Dumber To is a Contested Sequel.
Who's "Dumb" and who's "Dumber"? Many people would think it was about the main characters, but who's really the "Dumber" people in the movie here; the idiots, or the villains who believe the idiots are actually competent and intelligent?
If Mary had been single as Lloyd hoped and if they had gotten together, she might have been...Mary Christmas.
Sequelitis: The Farrely brothers had nothing to do with either Dumb and Dumberer (not to be confused with Dumb and Dumber To, which had The Farrelly brothers involved), or the short-lived animated TV series. Mediocrity ensues.
The toilet scene. Although no feces are shown on-screen, the sound design gives the viewer a rather vivid mental image.
They Changed It, Now It Sucks!: The unrated cut is often regarded as less funny than the theatrical version, because numerous gags that previously worked just fine with sharp editing have now been stretched out to the point that they become a lot more awkward and off-putting, and the jokes added back in are just plain awkward and off-putting, having been cut the first time for a good reason.
Took the Bad Film Seriously: The only aspect of Dumb and Dumberer to be consistently praised was Eric Christian Olsen's performance as the young Lloyd, with most critics finding him perfectly believable as a younger version of Jim Carrey.