i say sport what you want and fly the colors that you are proud of... mud runners do the same as well...
same for some military guys.... military tats, shirts, shorts, hats.... some people think i prob walk around the gym as if im gi joe... granted lets hope youre not looking like youre in a costume. other military you would never know because they dont fly the colors, which is also cool.
but for me id be hard pressed to say that no matter what i wear i always have some of military symbol. whether its a ball cap, unit tshirts, a lapel pin on a suit or cut-off fatigue shorts... (although i do believe in recycling good clothing and trying to save money)
its also a non verbal way to communicate... especially with others of common interest/background and maybe make a connection.
with that said ill qualify it further by saying being a poster child or a show off would be a major turn off. humility goes a long way.
what really annoys me are folks who wear a race or competition shirt or military something and when asked about it... they never did it! = poser
if you did be proud and wear it, if that what you want. fuk everyone else.
is it vanity? mmm perhaps... after all personalized vehicle license plates are referred to as Vanity Plates right?