European Eating?

When I was a kid growing up, I was taught to cut my food and then put down the knife and return my fork to my right hand. After all, I am right handed.

So what's up with all these people who dine with utensils in both hands all the time?They cut their food bite-by-bite and and shovel food into their mouth with the left hand holding the fork upside-down. Am I the only person who finds this offensive? Isn't it bad manners to put an upside-down fork into your mouth?