how to not take things personal

i'm a paranoid person and deal with a personality disorder and i tend to take everything personal sometimes...like earlier at the supermarket, i was wearing my knights templar t shirt...and i saw some other man with a blue superman t shirt on...and i instantly felt offended and took that personally, because i thought he was aiming that superman message at me....like subliminally saying i am like superman...and i hate superman.

should i have took that personal? how to not take things like that, - a man wearing a t shirt i don't like- personally?