I never knew there was a name for this till today but I was reading on another forum that specific things can trigger you into a state that can be described as ''a really strong tingling sensation along your scalp and a huge sense of euphora/happiness + numbness of your body'' . Mine were (and I'm not joking or trolling) : one of my childhood friends telling me which stamps out of my collection he had or not, my dog licking himself and more recently, haircuts.
I don't know why it's called ''orgasm'' because it's more like a drug induced, relaxing mood. I had no idea this was a thing and it had a name. There's tons of videos on YT with all sorts of ''triggers''.
en.wikipedia.org/wiki/Autonomous_sensory_meridian_response