It is bad enough when you know you must endure really uncomfortable and even painful procedures because of your stupidity. It is so much worse when someone talks to you like you are 8 years old.
If I ever talked to my clients the way I’ve been talked to I wouldn’t have work. Sometimes I do have to clean up self-inflicted mistakes on computers. I never ever treat someone unprofessionally. I don’t tell anyone 18 times how important it is to do one thing or another.