ENLIGHTENED!!!

Right!? I feel the exact same way. Seeing that makes me want to return the garbage inside the rightful trash bin (aka their cars).

WHAT!? HAHA! WOW! I would've done the same thing! Good on you, hermano! I'm surprised (and relieved) you didn't force your friend to eat the trash after he picked it up. It's great that he learned his lesson though. One less litterer foiled by your effort. Gold star for you!

Your grammar was correct, no need to be conscious about it :) I'm not a native English speaker as well, so I would never judge :)