I got harangued for half an hour by a hairdresser once. I don't even remember how the topic came up. Needless to say, it was the last time I went to that shop!

These days I have a better cork for that conversation. Asked about what kind of wedding I'd like to have, I can either say, "Been there, done that, SO glad I never have to do it again!" (absolute truth) or, "I tried that once. It didn't work out so well." (again, absolute truth but with a false implication). Either of those will probably derail the topic unless the hairdresser is actively malicious instead of just clueless.