sourpuss

In "Public Speaking for Dummies" Malcom Kushner says:

"Don't judge the entire audience by the reactions of a single person. This tip sounds obvious, but speakers do it all the time. You may see one sourpuss who won't crack a smile. You'll become obsessed with this person and make all your speaking decisions based on his or her reaction. That's usually a mistake, because nothing you do will work with the sourpuss, and you'll get nervous, feel you're bombing, and screw up."

Sounds like good advice for life. Love and try to connect with everyone. But don't get hung up on trying to please those who can never be pleased.