Please state in which country your phrase tends to be used, what the phrase is, and what it should be.
Example:
In America, recently came across “back-petal”, instead of back-pedal. Also, still hearing “for all intensive purposes” instead of “for all intents and purposes”.
“The proof is in the pudding.”
The actual phrase is: “The proof of the pudding is in the eating.”
It means that your dessert might look and smell delicious, but if you fucked up the recipe, say by using salt instead of sugar, then it will taste bad. You won’t know for sure until you eat it. So, a plan might look good on paper but be a disaster when implemented.
“The proof is in the pudding” doesn’t mean anything.