I am American. I grew up pretty poor and we didn't go out to eat when I was a kid. When I was about 15 I went to a diner. My uncultured friends and I didn't lea

I am American. I grew up pretty poor and we didn't go out to eat when I was a kid. When I was about 15 I went to a diner. My uncultured friends and I didn't leave a tip, not because we didn't want to, we legitimately just forgot to leave a tip. I would never forget now since 1) I pay by card and they have a tip line and 2) I am used to eating out now. The waitress followed us outside to the parking lot demanding a tip, it was awfully hostile.