What it is:
Free lunch is a phrase used to describe getting something for nothing.
How it works/Example:
There is no such thing as a free lunch.
Why it matters:
There are many things in life that seem to come for free: clean air, elementary school, a good-looking wife for example. Although these things indeed do not come with a blatant financial price or transaction attached at the time of use, we all know that our taxes pay to keep the air clean and operate schools, for example. And of course, nobody gets a good-looking wife without paying for a few dinners and a ring.