Strangest phenomenon ever to happen

My chest jumped

Lying still on my back very much awake alert and relaxed and with nothing attributible to any cause I can think of that could possibly literally move me in such a way.

In such a way

The first problem is that I don't have the skeleton or musculature to move in the vertical plane from the horizontal plan supine. It jumped violently without warning significantly far to bounce the rest of my body and the bed. I experienced no sensation of pressure as of upon any point of bearing as of any outside or inner force would necessarily exert to cause such a motion. Although it was so mysterious, sudden and violent I was not startled by the phenomenon.

wtf

I still do not know. It happened dozens of times on several different days I have no idea specifically.