OP is probably not an American. In the US it's quite normal to eat alone, in Europe (with a few exceptions) it's extremely odd to eat or drink alone at a bar or restaurant. Germany is particularly bad at this, and as someone who's had to travel across Europe for years for work, it took a lot of time to get over the odd stares in most places.

It's one of my favorite things about the US, being solo is way more accepted than in most of the rest of the West.