What is a good come back for "Condescending people"...including doctors?

How about: Please don't patronize me - I am an adult. Don't talk down to me. One more thing, especially for specialists: Why do you feel that you need to treat me like a dummy, you should be glad I'm asking/telling you this - an informed patient has done 1/2 your leg work for you by reading up. I intend to be an active participant in my own health, thank you.