Warranted but harsh criticism

I am usually unsuccessful at tuning out ambient noise, other people's conversations and the like, which is how I've gotten myself into trouble several times, most recently at work.

I walked into the nurses' station and a conversation between two nurses, "What is the Twin RX?" "It's a treatment." "For what?" "Hepatitis." *TV 'wrong' noise here*

There is no treatment for hepatitis. The Twin Rx is a vaccine (preventative measure) against hepatitis A and B. It was with this information that I interjected into the conversation.

And the nurse handing out the wrong information says, "You know what the problem is here, the problem is that I wasn't talking to you. If I was talking to you, I could understand why you're confused, but I wasn't talking to you. B understands me, don't you? [B nods]. So that's the problem here."

Oh smack.

He was really harsh, which stung, but what bothered me more was the criticism; I hate being called out on my weaknesses. (Funny, who does?) In his defense, it must get old having someone correct you, as I have done so before. Then again, it gets old having to fix someone's errors from erroneous information, too.