I was touch aviodant, I put it down to never being cuddled or hugged as a child so if someone did touch me it felt odd, uncomfortable. I didn't know how to react so I would flinch away.
I'm not so bad now.
I work at a foster school and many of those children do not like to be touched, sometimes touch to them has been a painful thing, a punch or slap. Can take a long time for a kind touch to be tolerated.