This is also one of my pet peeves. I like to do things myself if that's what they're designed for, and I hate it when over conscientious staff come over and want to help, and end up doing it for you. I know they're trying to be nice and helpful, but some people are smart enough to "self-service" when it's meant to be self service.
i rather let them serve me - find it easier to go up to the counter and let them sort everything out whilst i twiddle my thumbs haha.
too old to learn the technology thing i think