Skinny People Only Please!!!

Well, wasn't I suprised when someone else fed me a very high dose of my own medicine...they stated their opinion....outloud.....
I was waiting to get into the elevator at the office building I work in.  Finally the doors opened, and there was a cart full of chairs, along with the 2 men manning the cart, there was also another woman.  The men told me to come in, even though I was going to wait for the next car.  We arrived on the main floor, and then one gentleman instructed myself and the woman to go ahead. (I love men like this), I then walked off, and another woman I know from the building was waiting to go on the elevator, I then laughed to her, and said "Skinny People Only."  I didn't offend the person I said it to, she saw the joke fit the situation, as she saw me turn sideways and squeeze me way out between the doors and cart of chairs. (She too was skinny)  However, the woman behind me (also skinny), sighed and said "How rude you young people are."  First off, it was a simple comment which shouldn't have been offensive, and the hilarity was obvious, plus I didn't say it directly to her, but to the woman walking on, who I know. 
I found it ironic that I often find myself making comments about "the youth of today."   And someone had the nerve to categorize me as one of these disrepectful youths. 
I still have no idea how I had offended her.  Perhaps she, like myself, just likes to comment on random things.  Or perhaps she simply hates the youth of today, and their comments.
I even thought after that I should chase her down and ask her why it bothered her, and also to ask why she thinks I am a youth of today...I'm in my late twenties for crying out loud.  Why bother chasing her, it's irrelevant anyway.  (I will watch for her again though, in the elevator, perhaps I've met my match!!!)
If I find myself in a similar situation will I make a similar comment to the one I made today...why yes, of course I will!!!