“Head over heels.” But wait, isn’t that the normal state of things? So what’s your point?
“Heels over head” would make a lot more sense.
It seems to me that in the early 20th century, a first down was awarded for 9 yards (at least in some collegiate competitions, anyway). My father had a program from a 1910 (or was it 1911?) game, between Carlisle and some other team* but it mentioned a rule change for that year was that a first down would require 10 yards to be made, not 9 as it had been in previous years. My father kept the program (it had been his father’s), not for that tidbit, but because of one of the players, Jim Thorpe.
*In using Wikipedia, it just may have been the 1911 game between Carlisle and Syracuse, one that Syracuse won and I believe my Grandfather was a child living in Syracuse at the time. As this was over 100 years ago, anyone who was there is dead (as is my father), I cannot verify this info. I do think I may be able to find that program, though. I will put it as a high priority, due, in part, to this thread.
Sometimes you eat the bear … and sometimes the bear eats you.
Seriously, how may people that you know eat bear? How many have been eaten by a bear? Probably not that many.
Well, I was thinking about asking you out on a date…
What goes around, comes around.
Not always, and not often.
I haven’t eaten bear. Who has?
People often like to get ‘conflate-y’ over this one, conflating “reason” with “cause”. Sure, there is a cause for every action or occurrence, that’s pretty undisputable. But a pre-ordained “reason” is another matter completely.
I fucking hate this one in particular, being a paraplegic wheelchair user. I don’t think I need to say more. :dubious:
I hear this one so often, “Yeah, no…” It’s so annoying. And confusing.
“ass over teakettle” 
Well, if we want to nitpick, it would have to be something like:
You cannot consume your cake, and then expect to still be in possession of it, other than for a brief period wherein it remains, albeit vastly altered or in peices, in your digestive system. Eventually components of the now extinct cake will be incorprated into your corporeal body, but they will no longer be in cake form.
That’s one. My old man used to say “ass over tea cups” and it doesn’t make any sense either. I wonder if it’s referring to some kind of Jack & Jill type story.
Actually, no one knows where it comes from. There are a lot of claimed etymologies, but none of them is supported by evidence. I’ve seen claims that it refers to the amount of concrete in a cement truck (which actually isn’t nine cubic yards), or that it’s the length of a full bolt of cloth (which actually isn’t nine yards). The academics who study such things have never come up with evidence showing what the phrase originally referred to.
As for “have one’s cake and eat it” - I believe in the U.K. the phrase is usually “eat one’s cake and have it.” This doesn’t flow as smoothly (in my opinion), but the word order makes more sense.
The assumption of sarcasm might be a reasonable one on this board, but I’m not convinced that it’s an ironic inversion in most cases where this extremely annoying phrase is used. People who I interact with and don’t understand sarcasm even if they are hit over the head with it use “could care less” in all seriousness, not realising how idiotic it sounds. Sarcasm needs to be identifiable as sarcasm, otherwise it doesn’t have any meaning.
I’m as exercised about the usage of “could care less” as you are about people complaining about it. I agree that language doesn’t always have to make sense, but a phrase that means the exact opposite of what you’re trying to imply doesn’t exactly inspire confidence. I most definitely could care less about this.
But people have hunted (and eaten) bear. The saying would make LESS sense if it went, “Sometimes you eat the deer… And sometimes the deer eats you!”
Muscle memory
I mean these sayings are all metaphors, so they don’t necessarily have to relate to your personal experience (or even reality).
I love the “opposite aphorisms”, like
“Two heads are better than one.”
-vs-
“Too many cooks spoil the broth.”
“'Tis better to have loved and lost, than never to have loved at all.”
-vs-
“Owner of a lonely heart is much better than an owner of a broken heart.”
“Look before you leap.”
-vs-
“He who hesitates is lost.”
“Better safe than sorry.”
-vs-
“Nothing ventured, nothing gained.”
“The more, the merrier.”
-vs-
“Two’s company, three’s a crowd.”
“To thine own self be true.”
-vs-
“When in Rome, do as the Romans do.”
Never look a gift horse in the mouth, but beware of Greeks bearing gifts.
The full quote is “All that glisters is not gold; / Often have you heard that told.” The structure of the first line is meant to scan correctly.
Cecil has a whole column on this. Unfortunately, I’m on a tablet with limited CP abilities, so I can’t link you to the column, but if you go to the archives and do a search on the phrase, you should find it.