I don't get this thing about people with autism/Asperger's having a child-like side when everyone seems to have one.
I'm a 26 year old with Asperger's and some people have been like "you have the mind of a 12-14 year old." I will admit I do have a childish side but I also have other sides that are very different, I feel like 6 very different people all crammed in one. Smart person, dumb person, mature person, childish person, normal person and strange person.
My childish side often involves me laughing at humour that isn't really for my age like YTPs which I've enjoyed for years. I also like to analyse things that aren't the kind of things you'd expect someone like me to analyse, such as this https://www.reddit.com/r/nonmurdermysteries/comments/1cf8ohp/what_does_the_magic_house_in_teletubbies_mean/
I've seen many other people who seem way more childish than me like Disney adults who obsess over Disney, like I love Disney too but not to the extant they do. Most of their classic fairytale movies I only like out of nostalgia and if they came out today I don't think I'd be into them at all.
Or when adults are around babies they talk in baby talk which I've never done as I find it cringe.
I used to be a brony at 16 too.