Another super-O

I wasn't expecting much last night but got the best super-O in weeks that I could actually enjoy without interruption for a change.
At first I thought it was going to be dud session. No sensations at all for the first 5-10 minutes and I almost gave up. The it started to build, very slowly. As I slipped into an orgasm it immediately became a whole body experience, electricity shooting through me into my arms and legs and I was determined to enjoy it to the full. Wave after wave of orgasmic energy flowed into every bit of me, my body convulsed and I could hardly catch my breath. I love feeling of losing control giving in to the intensity if the pleasure flowing inside me. It was like magic and lasted 20-30 minutes.
I'm not sure quite why some sessions give me a super-O, others just a pelvic orgasm, although I throughly enjoy those as well. The super-Os seem to take longer to develop, I'm not sure it's got anything to do with relaxation, I'm going to keep experimenting.