We often use phrases and terms we have learned from oral language tradition without really giving them much thought. One of those that is frequently mixed up is a person getting their "just deserts". Many have blithely uttered this schadenfreude-laden term under the misunderstanding that if they did write the phrase down it would be "just desserts".
I know, as children many of us were often told there would be no dessert unless we finished the main course. So perhaps one could construe that getting dessert is getting what you deserve, having met the eligibility criteria by stuffing those Brussels sprouts down the hatch (blurgh). And in Australian English, desert and dessert are homonyms, so one could be excused for getting it wrong.
From now on though, if you have ever cause to write the phrase down, be sure to use one s because the word's root is the verb to deserve. The saying applies to someone receiving just what they deserve. It seems to have a negative connotation in modern use. Let's put it this way, I have never heard anyone say "Well, she certainly got her just deserts" after seeing an athlete win a gold medal.
Check out this list of common phrases that people frequently get wrong. Are any of them surprises to you?