I've had SPD, or Sensory Processing Disorder, my whole life. It's made me a little weird - it's meant I can't go on rollercoasters, or eat foods like mashed potatoes without gagging. I've had trouble driving a car or understanding verbal instructions, making me look like a dumbass. It's made me extremely anti-social.
It's also made me very physically sensitive.
This has meant great things for my sexual partners, because I've been so sensitive to their touches. This also may in fact be one of the reasons why I like being shampooed, or just washed in general, and why I craved being touched and massaged by my boyfriends. I feel it more than others can, and it feels extra amazing. I guess that's a decent trade-off for all the crap I've had to endure with the disorder.