From 15 to 19 years old (currently) I've worked as a cashier in a grocery store, and I think it has really truly tought me a lot about speaking with strangers. At first, the occasional laugh hurt my feelings a lot but over time I've gotten used to it. But I also think not everyone who laughs are actual intentional assholes. Like as much as it sucks, speech is just taken for granted in soceity and people don't know how to react when someone doesn't live up to their social expectations by not being able to speak properly. You can't really blame them, but hopefully they learn how to deal with stutterers over time. But I mean yeah, the actual assholes do exist.