There is a children's book called If You Give a Mouse a Cookie, which deals, as best I recall, with the greed inherent in the human condition, and how, when given something, people will take more. It's as if Ayn Rand wrote a children's book, after having acquired an idea of prosaic brevity.
There is a mouse, and it wants a cookie. So you oblige, and now it wants milk. Well this is bullshit, you think, I just gave you a cookie, stop being a freeloading pinko and who the hell is John Galt?, but whatever, no, I'm pretty sure mice are lactose intolerant anyway. But this is not how the narrative plays out. Our overly-empathetic protagonist does give the mouse milk, and then more things, and more, until all property and ideas are shared equally and there is nothing, nothing by which a man can distinguish himself, either in terms of material or ideas, and indeed, the very idea of merit has been stricken down.
Anyway, there is this book, which may or may not be exactly about that. It's been a while since I've read it. But the message, mostly, is that mice are greedy little sociopaths, and kids, hold on to your damn cookies. Clearly, explicit though this life lesson is, I failed to internalize it.
Being close to an art museum, my shop is frequented by field-tripping students. Today was such a day, and a an army of yellow-clad grade schoolers stormed in, milled about, bought nothing, and then asked for water. Just one cup of water, for free. But it's hot out, I thought. There is no harm in this, and anyway, think of the children.
So I presented the cup, smiled, thanked, and went back to wiping off a portafilter or something. But the chum was in the water, blood spreading, and the predators frenzied. They swarmed the counter, crowding out two would-be customers, demanding, water, more water, then refills, then more ice, and samples too, all for free, this, that, no money, gimmegimmegimme.
If you give a kid a cup of water, all the rest will descend upon you like piranhas, tearing and ripping at your supplies and sanity until barely, at the end, grasping at the tatters and threads, they leave you to clean up.