"The proof of the pudding is in the eating"

The proof of the pudding is in the eating is a proverb that means "You will not fully comprehend it until you try it" or "results are what count." It is frequently rendered in the shorter form The proof is in the pudding, which dates back to the 1920s and came into common use in the United States in the 1950s. The American Heritage Dictionary trims it even further, to proof in pudding. The proverb is ancient — it has been traced back to 1300 and was popularised by Cervantes in his Don Quixote of 1605. It’s sad that it has lasted so long, only to be corrupted in modern times.