I realize this is an older thread but I felt the need to share. I have these sensations all the time and have for many years. It was explained to me that when I dealt with past traumatic events I separated my mind from my body in order to avoid the pain. Also, had a therapist tell me that out of body experiences are not uncommon for survivors of trauma. When I experience the falling sensation it is like a mini flashback.

Also, if everything is relative then nothing is trivial.

Thanks for the opportunity to share.