We've always picked up our own litter, but my SIL has made me more "socially aware" of our surroundings. We were at the ball park this spring, and the team had dropped empty bags all around. I was picking up the ones I could identify as "our team's." I picked up a bag that had been dropped by the other team, and absent mindedly dropped it saying, "Not ours.'' SIL looked stricken....DD picked it up quickly. Without a word, it was my "ah ha" moment. Such a small insignificant piece of trash....but I chose not to be responsible for it. I guess I just assumed the other team's parents (or grandparents) would pick up after their kids. I don't really know, but it sure wouldn't have hurt me to add that bit of trash to my pile.
Now, as for lake trash....oh, don't get me started. I can't believe how many people just toss their beer cans over the side of the boat....or sit on the sand bar with a case and then leave the empties...in the box...and get back in the boat. And the little wine bottles they toss.. float, so they're a danger to boats and skiers. We'll have watermelon rind floating under our dock, along with beer cans on Sunday mornings...ug..