I really couldn't think of an embarrassing moment except for this:
I was an in-patient at the National Institutes of Health in Bethesda, Maryland back in the 70's. The hospital would let patients leave the hospital on a day pass but we had to be back by a certain time. One of the patients on my floor collected china and she asked me to go with her by bus to a wholesale place. While there, she bought a big soup urn and a few other things and she arrived at the price by bartering with them (which i had never seen anyone do in my life). We got back to the hospital and were riding on the elevator to return to our floor. The only other person on the elevator with us was an older, distinguished-looking gentleman with a cane, a suit coat and a fedora. We were laughing and talking about how she'd "jew'd them down" and scored a really good deal on some beautiful pieces. When the elevator made its next to last stop, the gentleman turned and faced us. If looks could kill, we'd have been dead right there. I can't remember word for word what he said anymore, but in the most dignified way he could muster, he let us know that not only was he Jewish, but he'd survived the Holocaust. Without cursing or flying into a rage, he gave us a tongue lashing and when he'd fished making his point, he cautioned us to think before we speak in the future, because you never know who's listening. With that, he exited the elevator. We rode the rest of the way in absolute silence. I felt like a worm. I think I was more ashamed than embarrassed because I've always thought I was better than that but he sure put me in my place, and rightly so. It was a lesson learned that I've never forgotten.