Too old?

I went into the local Whole Foods this evening to pick up some food and was questioned on my age for my credit card.  I paid for the bill using AMEX Gold card and the woman asked me how old I was.  I told her 30 and she seemed shocked and thought I was in grad school and 25.  I told her age doesn't matter for a credit card and it was odd for her to question my age based on that.  Somehow I was heated for her thinking I was younger, which is a first.  I had just shaven last night, was wearing shorts, a t-shirt, sandals and a backwards hat.  I think the clean shaven look and backwards hat threw her off, which begs the question - how old is too old to wear a hat backwards?  Some family and friends would say any age, since only d-bags wear their hat backwards (mostly a few family members would say/think this), but I've always rocked the reverse style throughout the years and still want to for a few more years.  I think  I'm cutting myself off the backwards hat at age 33.  

Speaking of reverse style and backwards hat........

(Don't worry, that's just my Uncle so its not weird.)