No I don't think that's right.

I like to eat junk food. I often make a pizza from my freezer. I like to eat chips. I do not litter.

Lots of people care a great deal about themselves while caring not at all about others.

I eat junk food. I treat my body like a trash can. Doesn't mean I treat the environment I live in the same. I share that environment with other people. While I may be trash inside, I don't extend that where it intrudes upon other people. I care more about others than myself. My environment is spotless, I am not.
I think you are wrong.

That is not true at all. If it was, I would litter everywhere, and my body freak, health-obsessed adopted sister would never have thrown plastic wrappers cheerfully out the window of the car. (She does not do that any more, we trained her to give a shit. Hard upbringing, from which our adoption lifted her.)

I don't think that's true. But seeing that the majority of litter around where i live is from McDonald's, it might also not be completely false