Strange Feeling

How do you explain to one a strange feeling? Did they ever experience it? Will they understand? For how long have I been trying to explain them my strange feeling?
"I can feel my bone leg and scalp-"
"Does it hurt?"
"Wh- uh, no it's-"
"Hollow?"
"Hollow? Um…"
"Cold?"
"…"
I have no idea how to describe it. It's just there. Same, but different from the other parts of my body.
I feel it only there, for a long, long time. But because I can't find the words to describe it, no one can tell me what it is.
So how can you explain an unexplained feeling?