That's not true at all as many men and women have died from heart attack during sex acts. The brain is never involved in the sex act and if it was humans would be unable to have sex. The primal brain is involved however.
The calmness comes from being exhausted and from the orgasm making you sleepy.
Every considered education back in the day or was wood chips more your kind of education and company?
21 and counting. I never did anything else in those 21 years and was here round the clock and wore diapers and got my nutrition from a hose into my arm.
Perhaps after 21 years I should at least take a shower?