American Stereotypes

Conversation today:

(Me looking at key ring): "Oh you drive a Ford?"
"Yeah. (surprised tone of voice) Do you have fords in America?"
Me: "Yeah, isn't it an American car?"
"Oh, right, it's just that Ford makes some smaller cars and I thought you all drove huge gas-guzzling ones in America."

This was said in a completely serious tone of voice.

Sparked a conversation about stereotypes - British, American (um, basically from what I can tell the entire world has pretty negative stereotypes of us, sorry guys), etc. I've had this conversation a few times with people this semester. I am continually amazed when the actions of a few, or even many, turn into views of how all people in one country behave. You're almost always going to find people who fit stereotypes for a specific country/group, but you're also almost always going to find people who completely blow every stereotype out of the water. It seems to me that people are people, and human nature should be the same no matter what part of the world you're in. Why do we feel such a need to group people instead of taking them on an individual basis?