Setting Off Shivers On My Own

Greetings !

This is my first thread here and I don't really know where to post this. Please feel free to move it to the appropriate forum if it's not okay here.

I don't know if everyone experiences this, but I can set off a shiver whenever I want (without goosebumps). I kinda slightly contract something at the back of my head, and I can easily trigger off a nice shiver that spreads through my head and shoulders. When I haven't done it in a long time (two days or so -- a 'short time' would be 20 minutes), the shiver can be stronger and spread even lower in my body. So far, the furthest I can go is the middle of my back. I started doing it unconsciously a few months ago, and I didn't stop because I love shivers ! They make us feel so good and comfortable. Also, I noticed that I tend to shiver out of embarassment in empathy for someone else. For instance, that kind of so-called 'funny' facebook posts that show someone who just got ridiculed make me shiver for that person. It works in real life too of course.

Do any other people experience this, or can everyone do it easily ? I'm kinda intrigued because I've never heard of such a thing.

Thank you for your help !