Ok, maybe that's a bit extreme, but I do try to avoid it as much as possible and here's why.
I'm from a small town. I generally go grocery shopping on my way home from work, which is in a different town, or in the city. I rarely see anyone I know there. On the other hand, if I go grocery shopping in the town I went to high school in, I see somebody from high school pretty much every single time.
This may not be an issue for some people. But for introvert me, it's just a social situation that I would rather avoid. I just like to get in and get out when I'm grocery shopping with little to no human interaction. I have been out of high school for 9 years, if I wanted to see somebody from high school, I would make the effort to see them.
So I'm walking through the grocery store last night and I meet up with this guy that I worked with in another life. We were never friends or anything, more just acquaintances. So then it leaves me wondering do I say hi? Do I just keep walking? What will he do? Well he said hi, and I was actually surprised. I guess he isn't one to avoid social situations like me....
Maybe I'm the minority here, but when you grocery shop, do you want to see people you know?