If you're easily offended: hello, how are you? Hope you're very well.
At the turn of 1980s/ '90s, cinema developed a penchant for differently abled siblings. Top of the list was Raymond Babbitt (Dustin Hoffman), brother to Tom Cruise's Charlie ('Charlie Babbitt is my brother') in Rain Man (1988). Charlie is after the fortune their father left to Raymond and together the brothers end up on a roadtrip that reveals the depths of the latter's autism: Raymond can recall numbers from the phone book he read in a motel; he counts toothpicks; he knows the number of male drivers killed in road accidents in 1986 (46,400) and the number of times Qantas planes have crashed (never). Raymond is also, as he often reminds us, 'an excellent driver'.
Five years later, Johnny Depp's Gilbert Grape was having to care for younger brother Arnie (Leonardo DiCaprio), as well as massively overweight mother Bonnie, when Becky (Juliette Lewis) hits town. Arnie has a predilection for Burger Barn and climbing the town's water tower in What's Eating Gilbert Grape? (I haven't included Forrest Gump here as I'm specifically interested in buddy movies though there may be an - admittedly abstruse - argument for including River Phoenix's narcoleptic hustler in My Own Private Idaho, Gus van Sant's 1991 update of Midnight Cowboy, which again starred Dustin Hoffman as a mannered sidekick.)
A slightly different take came when 1996 Belgian circus clown-turned-filmmaker Jaco Van Dormael teamed Down syndrome actor Pascal Duquenne with Daniel Auteuil for The Eighth Day (1996). Auteuil's businessman Harry is separated from his wife and kids when he, almost literally, runs into Duquenne's Georges, who becomes an immovable presence in Harry's life. (Van Dormael is another with huge lacunae in his directing CV: his follow-up to The Eighth Day, Mr Nobody, came 13 years later; his debut feature, Toto the Hero  is especially worth seeking out.)
While Charlie, Gilbert and Harry all discover there is more to life than their own worries, it is harder to accept that we should start living like their charges. It's all good and well looking at life through the eyes of innocents, but if we live this philosophy we end up like The Idiots. Lars von Trier had the final word on cinema's sentimental sympathies in 1998 - as Rain Man Raymond would say, 'Uh-oh.'