As Americans, we love to think that we're the center of the universe-- that everything revolves around us, and that all of our traditions are normal. Of course, we're not, and we can often be quickly humbled when we travel. Like in Italy when I tried to order an espresso to have with my meal (instead of after), the server looked at me as if I had three heads. Or, in the UK, when I tried to tip a bartender. They were more weirded out than appreciative.
But even if you're not a globe trotter, the internet is a quick and easy way to show us what we do differently. Recently, some non-American Redditors got together to point out all our weird little habits. I have one to add: putting ice in everything! Maybe it's controversial, but sometimes I want my water room temperature.