[baolongtrann]

> Why do people just not think twice about throwing their waste in a ditch or a river or leave their picnic at the beach?

I think there are two main reasons. First, many people don't have environmental awareness. They weren't taught. That's not to blame them, but it's just a fact. However the new generations are indeed educated on that subject. We were taught to not litter, to pick up the trash, etc. But this is where the second issue lies: when we don't follow the rules, nothing happens. No immediate consequences. Whereas in other developed countries, when people break the rules, they get fined, they get other people looking at them funny. That collective awareness helps enforce the simple rules.