Left right misperception

This has probably always been true, but I've been paying more attention to it recently, because I've been undergoing dental work: When I'm feeling around inside my mouth, with a tongue or with a toothbrush, I don't know what side of the mouth I'm in. Inside my mouth, I don't know left from right. If there's an itch in my right ear, I know it's the ear on the right. If I stub my left toe, I know it's my left toe. If I blink my left eye, I know it's my left eye. But inside my mouth, I'm lost. Usually I notice this when I'm brushing towards the back side — the back left side or the back right side. Like, who knows!

Of course, within half a second I can figure it out, by looking in the mirror, or remembering which side is missing the wisdom teeth. And now it's even easier since the hygienist was rooting around in the upper right roots the other day, to remember that it's the upper right that hurts.