Reminds me of a story one of my friends told me.
My friend and I both have a mental block in our minds that prevent us from throwing our trash anywhere but the trash cans. He and his family went to Vietnam for vacation a few years back. They hired a van and a driver to take them from city to city. At one point, they arrived at a restaurant and decided it was time to get rid of the trash. They went inside and asked the people where they could discard their trash. The people inside were absolutely offended by the very idea that a few tourists would throw their trash anywhere near their restaurant. Finally, the driver helped them out by taking everything and just dumping them on the road.
Apparently, it's not only habit in some places to litter. It's actually cultural in some places to throw your trash on the street. Why? Because anywhere else is considered offensive to the local people.
Disclaimer:
Occasionally, owing to the deficiency of the English language, I have used he/him/his meaning he or she/him or her/his or her in order to avoid awkwardness of style.
He, him, and his are not intended as exclusively masculine pronouns. They may refer to either sex or to both sexes!