Under the wire and out of steam

I've always found the expression you can't judge a book by its cover funny, because that's kind of how bookstores work. Between the title, author, critic quotations, illustrations, and blurbs, you may not be able to tell everything about a book from its cover, it's certainly a good place to start.

Gary Busey is one book you can
most certainly judge by its cover.

Of course, when the phrase first got popular, in mid-eighteen hundreds according to KnowYourPhrase.com, books had a lot less information on their covers. And yet, according to the Google Books Ngram viewer, the phrase is more popular in print than ever. But don't judge a book by its cover isn't the only popular phrase coined in a very different time.

With a face like this, what was
Martin Shkreli gonna do? Join the
Peace Corps?

It's your dime comes from when pay phones existed, and calls from such dinosaurs cost a dime. Mattresses aren't made from sacks of hay anymore, but we still hit they hay or hit the sack when we're tired. People who stay up late these days tend to prefer electric lighting, but they're still said to burn the midnight oil. Carnivals tend not to give out tobacco products as prizes anymore, but we still say close but no cigar. We don't use steam to power our vehicles anymore, yet when we're tired, we say we've run out of it. We left behind the human-limb-based economy at least a decade ago, but things still cost an arm and a leg. 

Robert Durst may have accidentally
confessed to murder back in 2015,
but the cold dead eyes have been
confessing his sins all along.

Riding shotgun refers to the guy on a stagecoach whose job it was to deter highway robbery. The practice dates back to the 1800s, at least, the the expression, according to PhraseFinder.org, is 20th century. We're not sure who coined the term - it appeared to have been around a while when it first appeared in print back in 1920. The old Westerns popularized the term, and by the 1950s, kids were using the term to refer to riding in the front seat of the family car. The term peaked in popularity back in the '60s, but it's still in wide use today.