"Rome wasn't built in a day"

Has an entirely different message to me. It's often used as a reminder to be patient, not to loose your temper, etc.

On the day Rome was founded Romulus killed his brother Remus and marked out the city of Rome, construction starts. This is my initial reaction.

The next thing the Romans, a group of men (probably criminals), did after founding Rome was to raid their neighbours and kidnap their women. Rome then makes war for the better part of a thousand years, eventually subjugating the known world.

I think it's better used as a reminder subjugation starts out in small measures. "Parliament just passed antiterrorism laws, I'm sure they're to protect us" "Rome wasn't built in a day"

"You cannot have a cake and eat it too?"
Bruv, if I have a cake in my hands, I am going to eat it.
It's like me giving a back massage to my girlfriend. Things are going to get groped.
Yes, I have a girlfriend. I will not be taking any questions.

Sleep like a baby. That is not what I'd consider a good night's sleep.

There are a number of idioms that MythBusters tested, some of which were disproven and some of which were confirmed/plausible.

It is easy to punch out of a paper bag.

10 pounds of poop will not fit in a 5-pound bag.

People can easily recognize the backs of their own hands.

Taking candy from a baby is not as easy as it sounds.

People may literally get cold feet when they are scared/timid.

If poop hits a fan it can indeed create a large mess.

You can teach an old dog new tricks.

With an enormous amount of force, it is possible to literally knock someone's socks off.

In a race, it is not literally better to hit the ground running.

You can polish poop.

Shooting fish in a barrel is fairly easy; the shock wave from a bullet can be enough to kill the fish.

A bull in a china shop will actively avoid hitting the shelves.

A rolling stone truly gathers no moss.

Finding a needle in a haystack is difficult, even with modern technology.

[EDIT: a couple of other idioms not in the idiom section of the link.

It is possible to make a balloon out of lead.

It is not possible to herd cats.

A goldfish's memory is not limited to three seconds.

]

The use of "quantum leap" isn't about comparing the absolute size of the change to quantum phenomena. It's about the lack of a smooth transition. Quantum leaps in physics are instantaneous transitions between states with no intermediate. That's the idea with the colloquialism: a sudden shift from one state to another without a smooth transitional period.

Not quite an idiom, but one of the senior managers at work keeps talking about Moore's Law in the context of AI stuff like it's some kind of fundamental law of the universe that any given technology will double in capability every 2 years

1. Moore observed that transistor density in microprocessors had historically been doubling every 18 months, and this trend more or less continued for a decade or so after he noted it
2. Density has nothing to do with the capability of technology that uses those microprocessors. The performance of the chips roughly doubled every couple of years, but there was a lot more going on with that than just transistor density
3. Moore's law hasn't held for at least the last decade

What doesn't kill you makes you stronger, does not hold true for many diseases including many cancers

The saying "shoot for the moon, even if you miss you'll land among the stars". No you won't, the stars are outside the solar system, they're much further away than the moon

Below par or under par. Used backwards by everyone. As a golfer, I want to be under par.

I hadn’t heard this take. Did David cheat by using the slingshot? Was that not allowed? Was this like a duel with rules?

"Positive feedback loop" to indicate a situation in which circumstances feeding into each other result in more good things happening, or "negative feedback loop" to indicate bad circumstances feeding into each other to result in more bad things happening.

I have worked with enough controls folks to know that positive feedback in a control loop often leads to instability (bad), while negative feedback in a control loop can be used to stabilize the system (good). It just comes down to the math in the situation.

So people saying that they are in a positive feedback loop can, to a controls person, sound counterintuitive. E.g. "I'm in a positive feedback loop of working out, having more energy as a result, and working out more, making me healthier!" would be momentarily confusing.

I did grad school at an engineering/STEM-focused school, and the campus psychiatrist actually used these terms correctly when discussing anxiety attacks! As an engineer myself, that made my nerdy heart happy 🤣

Another control theory phrase issue: The phrase "more optimal" is incorrect and very well may earn the speaker an "umm, actually" from any controls folks in the conversation. Optimality is not a scale--either something is optimal (with respect to a specific metric), or it isn't.

(EDIT: reducing verbosity)

There is a "learning curve" to it - used as "it will be easier after a while. It's the other way around. Learning curve is when you learn like crazy at first, but than after you knock out all the easy wins your progres slows dramaticaly.

Thunder only happens when it's rainin'

Players only love you when they're playin'

"Does a bear shit in the woods?"

Might be a regional thing but people would often say this as a sarcastic but emphatic "Yes" reply to people, particularly "obvious" answers.

Truth is, my personal observation is that they will make every opportunity to come out on the nearest road or field and shit there.

Obviously one could argue the pedantry (eg rural = woods, or most shit is in wooded areas) but my point is back to there actually being enough nuance to argue the point that they aren't making the point they think they are when they say that.

I'm fun at parties!