Are you familiar with ASMR?
I have had this for as long as I can remember. It is basically a physical response to certain auditory and sometimes visual stimuli. I remember experiencing this when I was very young. As just one example, I would get a "tingly feeling" or some kind of intense feeling when sitting in my dad's truck and watching/listening to the gas station attendant clean the windshield. Per Wikipedia:
Autonomous sensory meridian response (ASMR) is a term used for an experience characterized by a static-like or tingling sensation on the skin that typically begins on the scalp and moves down the back of the neck and upper spine. It has been compared with auditory-tactile synesthesia.[1][2] ASMR signifies the subjective experience of "low-grade euphoria" characterized by "a combination of positive feelings and a distinct static-like tingling sensation on the skin". It is most commonly triggered by specific acoustic, visual and digital media stimuli, and less commonly by intentional attentional control.
https://en.wikipedia.org/wiki/Autonomous_sensory_meridian_response
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Not sure when I first noticed it, but I'd guess in my young teens at the latest.
I recall trying to explain it to my mom, but she thought I was describing some weird sex thing, and she became visibly uncomfortable.
I didn't know the term ASMR or that other people experienced this until I stumbled upon an online article two or three years ago, when I learned that tapping/scraping fingernails are a very common trigger.
Although it's a acutely pleasant sensation, for me it's also decidedly non-sexual.
