If people have time to look and even CARE about what you have on and what you are wearing ... they need to get a life ... and/or they are not doing WDW right! I mean people are wearing MOUSE EARS for goodness sake!
I swear ... I couldn't tell you WHAT anyone wore or didn't wear. Now ... if you are in high school that is a different matter ... please feel free to be cool, cold, carry heavy bags, never without make-up ... etc ... but if you are BEYOND high school -- comfort is everything.
YES ... dorky (old) me does wear a fanny pack. 80's -- 80's ... HEY I RESEMBLE THAT REMARK ...
Wear whatever makes you feel ok ... or don't -- the decision is in your hands. Have fun!