They should just avoid talking about my job

This whole exchange is just weird, manplaining my job to me, or making assumptions about it. What does "and yet" mean? I'd only like my job if I sat around reading all day? I don't think I've ever had an exchange about being a librarian that didn't make the guy seem a bit (or a lot) like a jerk.

I'm trying to be less judgmental but people get on my nerves...