WHY is the trope "genius in their mid 30s to early 40s who solves crimes" so common when much funnier alternations of it exist, of whom some of them are:
local genius, who solves crimes, is 80 years old. bonus points if it's a group of local genius grandparents that all come with typical old people behaviours.
local genius whom it only takes a look to read you just memorised astrological birthcharts and can vaguely guess someone's birthday. they don't know shit about "reading someone" based on anything else than birthcharts.
local genius wants to solve crime, but gets their application rejected then joines a group of other geniuses that just fuck around and solve crime. bonus points if they even have a better quota in solved cases than the police.
local genius wants to solve crime, gets rejected and instead uses their genius to hinder everyone from their work. they are bored and they are going to make it everyone's problem.
local genius uses the duck test ("If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.") as their only evaluation for literally everything. they work as a lawyer, they never judged a person falsely.
local genius has a really uncommon and niche topic, such as for example knitting, in which they're good at. they get consulted to a crime scene. apparently no one understands that this is not their level of expertise. bonus points if all their knowledge of knitting can be applied to crimes.
local genius does not want to solve crime and they must have told that the poor guys that get sent to their door at least every second day a hundert times already.
local person is not a genius but for a reason they cannot explain everyone thinks they are. by sheer luck they manoeuvre the challenges their wellmeaning but pestering neighbours/friends/collegues present them.
not very funny but i think it would be quite cool: local genius is the most mentally and physically healthy person among their friends and family. everyone wants to know their secret, but all there is to is it that they just run into the woods for two hours every day where they scream really loudly and muse.
local genius swears up and down that loud heavy metal music is helping their bloodflow thus helping them think. local genius in this case has to think really intensely at night.
local genius and love interest™ fall in love over their shared ramblings. they listen to each others niche topic rants for hours without end, because they know how it is on both ends.
add on the things you'd like to see in the "local genius" trope