United States of America: Complimenting or striking up convos with strangers while out and about. I'm not sure if it's purely a Texas, US, or just suburban vs urban thing but I know I'm used to when I'm out and about just being like "Oh I like your shirt!" "I like your makeup!" etc. as I pass by someone if I feel inclined.

When I was in Toronto visiting a friend I noticed that people generally just didn't seem to want to be bothered, even for something positive and friendly like that. Again I'm not sure if this is a country to country thing or just an urban vs suburban divide thing, but it stood out to me.