Seeing those very common, very basic errors bugs me because it smacks of intentional ignorance. Example: I had a female classmate in high school, who was cute and ran with some other cute girls. She would ask me for help in some of her classes including literature and religion/philosophy (Jesuit school), and photography/dark room. I didn't mind helping out. But, she never seemed to try that hard to learn and use basic grammar and spelling, and didn't seem to care very much about. She was one of those girls who would sign your year book, "Your the best." Yet, despite her seeming lack of care, still she asked for my help. I still am cordial with her at high school reunions. She is married to another friend of mine. But, her FB page demonstrates the same intellectual laziness. That laziness is demonstrated in her posts by the way she writes them, her lack of thought, her politics, etc. Those basic grammatical errors, especially when one was provided an opportunity for a really excellent education, are symbolic of mental sloth. Seeing them really bugs me to this day.