It's an interesting question for a number of reasons. And such a good one!
First, I say interesting because humans are a social animal. These rules - no matter how random and arbitrary - are really important for people to function. Plus they aren't as arbitrary as one might think. Like it's not that great cornering someone's husband alone to be friends with, without properly acknowledging the wife. Sure, you may have nothing to say to the wife really; and you may have no interest in the man in "that way"; but it's about resources and claims on resources. Like time. Works the other way, of course.
Secondly because what society thinks is in no little part a product of our own imaginations and what the few people around us think (e.g., who is the great "they" - as in "they say"?). For example, it's more than ironic that I saw - and my apologies for even mentioning these things - a billboard for marijuana when tobacco billboards are illegal. My first thought was who are these people? But then I realised, they're two different sets of people.
Third, pink like high heels was originally designated for men - not women.
Fourth, many cultures - if not most - cultures are far more severe about categorizing things as masculine or feminine. It's ingrained in the very language with the masculine or feminine designation of nouns. English doesn't have that.
Fifth, there are differences between men and women... but it's not as extensive or where people think they are.
Sixth, society is an interesting thing. It relies on self-regulation more than enforcement and the rules are somewhat an outgrowth of our general tendency to think like this: I'm a girl so I limit myself to girl things.
But to answer the question: I most certainly do let society and religion define the norms for me. For me, it's a matter of organisation (IMHO, people don't do that well without norms), and they have an 'instutional' memory that I don't personally have but which is useful. On the other hand, I don't stay in the box. I accept that I defy certain norms and it's on my own head. I try not to be too much, though, because to repeat myself - I really do find other people have a really hard time getting on with themselves when the rules get too broken.
I also don't think clothes are that important an arena to maintain the norms. If we were a subsistence society, maybe I would. But we live in relative luxury and can afford to play...
Whoops! Accidentally wrote a book...