I had eight of them, all impacted (I have a very small mouth). Had to have them all extracted. Fortunately I was still popping pills at the time.
It’s typically a extra layer of bone inside your lower gum where your tongue sits. The link above isn’t actually all that gross, it’s just the inside of somebody’s mouth. I wanted to err on the side of caution.
Yes, I have all of mine. I am 43 and suspect that I will have them the rest of my life.