Nostalgia is such an intense feeling!! I've been aware of this for some time but I just pulled up a video with Pokemon video game songs that claimed it would be 'too nostalgic' and they were right! The emotion that derives from nostalgic encounters (encounters with media, mostly) is such an intense one and makes me...equally sad and wistful? Like I'm happy to be reliving, even partially, that old moment of happiness, but on the other hand I become almost desperate to recapture it.
Quite a few years ago I went through this recapturing phase really intensely, where I was desperate to find this old Beatrix Potter video I remember from my very early childhood. Once I found it, I was really happy but got put off by myself for being so adamant to return to a point in time where I couldn't have been but 3-5 years old (at most). This was before I was diagnosed, of course, and one thing my diagnosis (of ASD) has done for me is allow me to recontextualize certain behaviors that I thought were 'cringey' or 'age-inappropriate', but I still grapple with whether it's healthy or not to try to relive these moments.
I miss the innocence of being young. Even though my anxiety was already fairly debilitating at a young age, there was a lack of concern I had back then. For example, I'm not good at decision making, and at 24 years old, I'm dealing very heavily with how responsible I am for making my own decisions. But sometimes I wish I was just a child again.