Yeah, you're right. Seems like the older I get the more I run across those who are considerably less intelligent than is normal. What gets me is their use of the English language although I must admit sometimes I also see it here.
The use of the contraction of you are (you're) as your. Your is a personal pronoun signifying ownership. Likewise there for their. There is a place or location, their again tags ownership. There are more examples but why pick on them?
I'm not a scholar and disliked Engish in high school. I always figure that those who use "you know" so often are maybe a tad illerate. Some of the more popular sports figures use that phrase quite often.