Finns can be very introverted, which leaves some more outgoing people with the feeling that Finns are anti- (or a-) social and depressed. That's not the case. The Finnish culture just values introversion, privacy, and polite public behavior. This contrasts sharply with the European meme of the loud, outgoing, and rude American, and the two cultures see each other in extremes and play up the differences for humor on the Internet.
To a lesser degree, I felt that way after moving to Southern Californa from the East coast: https://pbs.twimg.com/media/Cvzm3sZWAAETO_b.jpg:large
I held a door open for someone when I was in NYC last time, which turned into a big mistake. Everyone else hadn't been paying attention and when they saw me holding open the door they must have assumed I was a doorman and everyone flooded through the open door not giving me the chance to catch back up to my group. Meanwhile in the Midwest, if someone is a few steps behind you and you let the door close, they're going to be complaining about how rude you were for hours.
Relatedly? "...an intact amygdala is necessary for feelings of discomfort following personal space violations, thus helping to automatically regulate interpersonal distance." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123873/
(Also, for those curious: Space Invaders: Personal Space and Autism "...it is possible that a dysfunction in the amygdala contributes to problems in maintaining an appropriate social distance in autism." - https://www.iancommunity.org/ssc/personal-space-autism)