Oh gosh I so feel what you’re describing, my friend, and it frustrates me that most adult can’t make the difference between “acting" childish and “being” childish:

While the first one of the outcome of our magnificient connection to our silly inner child, the second one is the result of emotional immaturity which stayed at the toddler stage because of trauma despite all the adulthood masks. Narcissists fit the latter scenario the most!