[[WMG: Alan is [[Franchise/TheElderScrolls Sanguine's]] champion.]]
Self-explanatory; Alan was given the drugs responsible for both movies as gifts from the Daedric Prince of Debauchery. And considering Sanguine's actions in ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]''...

[[WMG: The third film will lampshade a lot of the series' tropes.]]
For example, at the climax, someone, probably Alan, will tell Stu that "now is usually when you figure everything out".

[[WMG: Chow will die in the third movie.]]
And his final words will be "Toodaloo, mothafuckaaaaaa...!" or "...so long...gay boys..."
''Jossed'': It looks like he's going to die in one scene, but it ends up being averted.

[[WMG: Every time Stu is having a shitty day, he sings an improvised song about it.]]
He demonstrates proficiency singing and playing instruments, and both times his friends don't see anything amiss at him breaking into song. I think Stu has been doing this since he was very young, so often that his friends became used to it ages ago.

[[WMG: Chow [[spoiler: Invites himself to Alan's Wedding]]]]
And even after [[spoiler: realising Chow is a proper murderous villain Alan goes along with it for old times' sake.]]
* [[spoiler: confirmed]]

[[WMG: Alan has {{AspergerSyndrome}}.]]
Between the social awkwardness, the childlike demeanor and the insane amount of skill in a field (in this case, math), it wouldn't be out of the question to say that he may have it.