I guess I should have known what check nuts were, but I thought I'd better check up online just to make sure I wasn't on the wrong track. According to one dictionary they're a secondary nut, screwing down upon the primary nut to secure it or a nut which is screwed up tightly against another nut on the same bolt or screw, in order to prevent accidental unscrewing of the first nut.
I think that's probably a good description of some marriages: the secondary nut secures the primary nut (I don't say which person is which), or else one nut is screwed up tightly against the other nut to prevent accidental unscrewing. Accidental unscrewing of a person is to be avoided at all costs. I've come close to accidental unscrewing at times, and have been saved from it by the other nut. When I use the word nut I mean it in the most complementary sense, of course.
But in regard to nuts in general, apart from its normal use to signify those hard things we eat and which can sometimes crack our teeth, nuts is used as a way of saying - that's stupid, dopey, how-the-heck-did-you-ever-come-up-with-that-idea? It can also mean what is virtually the opposite: being nuts about something, extremely enthusiastic, in other words.
And nuts turns up in one of those innumerable (and untranslateable) English expressions that can mean pretty much whatever you like: elephant’s adenoids, cat’s miaow, ant’s pants, tiger’s spots, bullfrog’s beard, elephant’s instep, caterpillar’s kimono, turtle’s neck, duck’s quack, duck’s nuts, monkey’s eyebrows, gnat’s elbows, oyster’s earrings, snake’s hips, kipper’s knickers, elephant’s manicure, clam’s garter, eel’s ankle, leopard’s stripes, tadpole’s teddies, sardine’s whiskers, canary’s tusks, pig’s wings, cuckoo’s chin, and butterfly’s book. I'm indebted to Michael Quinion's wonderful website, World Wide Worlds (how's that for alliteration) for that list. (It's a site well worth visiting, if you're a word enthusiast, that is, if you're nuts about words.)
Still on the usage of nuts, here's a delightful line from Kim Fabricius, that theological doodler: How did Jesus overcome Satan in the wilderness? By proof-texting a proof-texter. That always drives them nuts.
And one other paragraph, from the poet Charles Simic: When my mother was very old and in a nursing home, she surprised me one day toward the end of her life by asking me if I still wrote poetry. When I blurted out that I still do, she stared at me with incomprehension. I had to repeat what I said, till she sighed and shook her head, probably thinking to herself this son of mine has always been a little nuts. Now that I’m in my seventies, I’m asked that question now and then by people who don’t know me well. Many of them, I suspect, hope to hear me say that I’ve come my senses and given up that foolish passion of my youth and are visibly surprised to hear me confess that I haven’t yet. They seem to think there is something downright unwholesome and even shocking about it, as if I were dating a high school girl, at my age, and going with her roller-skating that night.