Does it?

Years and years of practice my friend. Hours spent signing your signature over and over on sheets of paper until you get it right.

I find this incredibly difficult to understand.

Technically the post is correct. Your signature does just happen when you're an adult. That's when you start having to sign a shed load of documents and you get your signature groove on.

I've been signing things since I was 16, my signature is always different; I just do random squiggles.

I spent like a day figuring mine out and I love it

If it does then I missed it.

Once you adult..
My signature is still just my name written in cursive, I have yet to adult

I hate my signature, but my name sucks to write, so I'm doing the best I can...