it goes to show

go to show

To prove, demonstrate, or indicate that something is true. (Used especially in the phrase "just goes to show.") Their success just goes to show that you can't underestimate the power of good marketing. My grandfather's pocket watch still runs perfectly after all these years, which goes to show the level of craftsmanship put into it.
See also: show

it (just/only) goes to ˈshow (that...)

used to say that something is an example of a general truth or principle: He had all his money stolen? It just goes to show you should always lock your desk.
See also: goes, show