There are some things in this life that you just don't need to know. Why feet keep washing up in Canada and the US, for instance, or that some people splint when they poop. Add to this list the answer to why we all have chin dimples.
One TikTok user asked the question "what is this thing" before forcing his face at the camera and making his chin dimple at it. It turns out it was a question that a lot of people have. You have a chin all this time, but never really wonder what's going on down there, apparently. Maybe our curiosity is impeded by our nose, constantly blocking the view.
Science communicator Hank Green had an answer for him and other chin owners that people have found distressing.
"You have identified correctly a weird muscle, well done," Green said in his video reply, explaining that most muscles in our body connect bones, though there are quite a few exceptions. Your sphincters (of which you have many, but well done for thinking straight away of the one in your butt) for instance are ring-like muscles that pull on themselves in order to open and close.
In your face, you have muscles that connect to your skin. Try making some facial expressions (maybe practice your look of horror for when you discover what the human chin looks like on the inside) and you'll see these muscles in action.
The one that's causing upset to everybody is the mentalis muscle, a paired conical muscle that lives inside your chin. In conjunction with all your other muscles, it helps you to express all kinds of emotions, not just produce dimples or the infamous "chinny reckon".
As useful as it is, it's best left (as with all your other facial muscles, to be fair) on the inside of your face. A lot of people agree with this sentiment.
If you contract the muscles, this is what creates dimples. So the Internet got the explanation – but Jesus, Mary, Joseph, and the wee donkey, they wish they didn't.