So we are told that human adults have 206 bones the only reason we say 206 is because the famous anatomist Henry Gray decided that was the number in the 1950s. Now, we know way more about how bones change, and it turns out your bone count decreases by about 25 bones from your 20s to old age. I mean, the bones aren't disappearing, mind you, they're fusing as a six to seven week old fetus, you started growing bones. Hundreds of bones! At your peak, you had about 800 little growing bones, most of which connected to form bigger ones. So by the time you were born, you only had a few hundred. This fusion continues all throughout childhood but it doesn't stop after puberty. In their mid 20s people have about 215 bones, but by their mid 40s, that decreases to about 209 or so. And senior citizens are left with about 190. So yeah, at some point, you'll have 206 bones, but not for long!