That’s okay, feeling nostalgic for something one used to love is perfectly normal. But it’s not necessarily the case of the thing you used to love going downwards; it might be the case you’ve either outgrown it, or lost interest with it. And that’s fine! Absolutely normal! I’ve many interests I used to have, that I hold dear memories with, but couldn’t see myself ever looking at again.
It’s just how it is.
And, ah, my point with your age was merely a “I want this type of content, even though I’m not age appropriate for it yet” argument. Since, you joined a 13+ app when you were ten, and want (what I assume) content that’s on the mature side… Which, by international law, is 18+, which you are not yet. And, I’m sure your parents couldn’t stop you from looking either up, if you wanted to 