Psychiatrists used to test several things in your brain by asking you to explain what various proverbs mean. Because more than one things is being measured, the trend is away from this now, but you can cover a lot of ground quickly - getting a sense of not only ability to abstract, but whether high emotion words distract one. For example, "Don't throw the baby out with the bath water," might provoke an isolated-feeling person to get hung up on the part that a baby is being thrown out. A person of limited intellect might make no sense of it at all.
"The grass is always greener on the other side of the fence" was a popular first proverb. Its abstraction was minimal, and there were no emotion-laden words in it. No obvious ones, anyway. Psychotic people can become stimulated by pretty unlikely things. But most people would get this one right. They had heard some variant of it and understood the comment.
Intentionally more problematic, because it is both more abstract and more ambiguous, is "People who live in glass houses shouldn't throw stones." Even if you know it well and get the point upon hearing it, it's a little difficult to put into words the first time. I never quite worked out for myself, however: is the important part of "glass" in the proverb that it is brittle or that it is transparent? Both preserve the sense of the proverb, though with a different feeling. Perhaps they are also meant to reinforce each other, giving one a double reason not to throw stones.
Which aspect dominates for you in contemplating the proverb?