Associate
I sometimes get a jolt as I relax too quickly as I fall asleep, the surprise causes me to wake partially with a jolt. I'm conscious when it occurs but my whole body spasms.
Wow. I can assure you that you're not alone with that one. I've 'caught' myself with that a few times of an average year. However, more alarmingly I can relate to the dsps description, although I've never felt it to be a problem in my adult life it was a huge problem for me in my school days at least since I was around seven or eight years old (or about as far as I can recall sleeping odd hours), out of sync with society at large.
I don't find it disconcerting, but I do feel that this is what the term night owl probably refers to. Interesting that the condition appears in approximately 3 in 2000 people according to wiki. Over the last eighteen years or so I've come to cycle through over a month. Good for dealing with US clients. All in all not a major problem for me to deal with as my life is fairly diverse.