Nostalgia.
Behind the majority of the nostalgic tendencies, I see an attempt to 'go back and fix it'.
The roots of mine definitely lie in that feeling. I was a kid in the '90-s, when everything was all about diversity and inclusivity according to the commercials and the media - as we, in the real-life, were judging each other and measuring our classmates' value via the height of their platforms, or the fact that do they wear the same pale-blue Shenzhen tank top as the entire class or not. Or as the platforms were out, there came another fade that I could not follow because I already lost the plot one similarly working fade before. I felt stupid, I leaned in the role of the unpopular kid, and actually - although there were a lot of ill-willed interactions between my classmates and me these days - no one was to blame. These are tendencies, often grind experienced, 'wise' adults in, how could adolescents and kids stay out? 
I definitely would go back with the mindset of my present self and fix stuff.
Don't get embarrassed by learning a language - Serbian, for the closest example as I am working solely on it (of course besides amending my English, which I learn from my childhood). Although now I have content for it (the folk dance ensemble and their circles) and then I had only the music I listened to, but there are plenty of people who learn a language that way, alone in their rooms, listening to music and reading a lot and somehow they get to speaking and thinking that language.
Don't get embarrassed by learning and practicing anything, basically. Music, sports, anything that requires work and does not 'go' for the first try. Talent is not that you are born with an exact skill. 
Don't stick to someone based on one attribute or the fact they are not the same character I see all day - like they're from abroad, they have a strange accent, or speak a different dialect than me. Something that seems like a link between me and the world outside - because the world is outside and I am in. I don't consider myself a person that easily gets bored and requires full-time entertainment. but mandatorily being closed together with only yourself is exhausting. Often intangible exhausting, because all this is a matter of realizations coming at the right time, practical intelligence, and a sense of rhythm. If you take one out, everything collapses. I lacked practical intelligence, and so this lack held back the realizations and created a lagging rhythm. Something that I am fixing as an adult and getting tired sometimes I pose the question is this something that one can fix? When I am not that tired, I know that yes, a lot of people fixed worse twists through history, so there is nothing tragic here.