"By three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest." - Confucius
Several years ago I adopted a section of Texas highway. I invited people to help me pick up trash and no one showed. I came across a snake and other strange things. I couldn't believe all of the cigarette butts. I finally filled three or four huge bags and called it quits.
I grew up in Lubbock where the 'KEEP LUBBOCK BEAUTIFUL' campaign really taught us not to litter. In the small town where I grew up, there was a running joke that we knew who'd been around based on whether or not any trash was on the street.
San Antonio was the first city where I saw time after time people improperly discarding trash and not thinking twice. I haven't seen it recently, so maybe the word is out. JMD