I am far from a perfect punctuater - I over comma like nobody's business. (I also make up words like "punctuater", but that is not what we're talking about right now.) But I understand the difference between a possessive and a plural and it drives me absolutely crazy when people completely reject the notion of apostrophes, or much more commonly throw it in whenever an S comes to live at the end of a word.
Today I was at Winco, a grocery store that is pretty sketchy, but also highly entertaining. I end up taking pictures of funny things I see there more than anywhere else. One time there was a box of dog food called "Moist and Meaty" with the phrase "That's what she said" handwritten on it. I promptly took a picture and sent it to everyone I know. One time there was a crate of bath mats that were essentially rag rugs made out of jersey knit, and the tag said, "Luxury Bath Rugs." That was so preposterous, I snapped up a picture. But today, there were multiple endcaps near the registers that have new (at least to my notice) signs up.