Giving things for free often leads to making enemies.

That sounds harsh, but it's the truth.
There's a trash picker auntie on the first floor of my community.
When I throw away trash, she asks me several times, "Young man, are you throwing away this cardboard?"
But every time I say, "No, I’m keeping it to sell in the car."
Her face would look unhappy right then, I pretend not to see, and turn to walk away.
It's just a few pieces of cardboard, right?
It's not that I’m stingy, but I’ve been taught a lesson.
Once when I was hospitalized, my hand was injured, so I could only order takeout.
A 60-something old man on the neighboring bed, with children and grandchildren, but no one to visit him.
He would just nibble on a steamed bun every day, I saw him rummaging through the takeout boxes I threw away, picking out leftovers to eat.
I felt sorry inside, so I always brought him a portion when I ordered takeout.
He didn’t say thank you, just took it and ate.
I didn’t pay attention to it.
A week went by like that, and one day my colleagues and I went out to eat, came back late, and didn’t bring him any food.
He was lying on the bed, staring at me intently, and said, "You go out to eat the good stuff and drink the best, and you don’t bring me any food? I’ve been hungry all night."
I brought him a week’s worth of food, and he didn’t thank me, but instead felt I owed him.
The person on the next bed also started criticizing me, saying, "How can young people be so inconsiderate?"
Since then, I never brought him food again.
He came looking for me again.
I directly told him, "I’m not your son, you’ve got the wrong person."
Now that auntie asks me for cardboard, I will never give it to her.
I sell it or throw it into the trash, and let her pick it up herself.
That’s her business, and it has nothing to do with me.