Interesting - I was a cashier for quite some time, and I actually found it pretty rewarding. I got to see everybody from town, and learned that I like working.

That said, I was around 16, so I didn't have to endure "you don't want to end up like him" comments.

What kind of parenting is that? "you don't want to end up like him/her"? The cashier has a job, is a productive member of society. Whatever. There are all sorts of people and all sorts of jobs that need doing.

First rule of writing: write what you know!