Today I learned that when you go to a new dentist for the first time and you start out the appointment by saying, "Listen, I know all about flossing and that I'm supposed to do it every day - and while I do try to do that, I'll be honest with you - I don't. I know I could/should floss more often. So if we could just skip the flossing lecture altogether, I would really appreciate it." that you won't get the flossing lecture and the appointment might actually go surprisingly well and you might even want to return to that dentist in the future.
Of course I may have just found a really awesome dentist and my lecture may have had nothing to do with my good experience, but I don't think it hurt.