Why is Kirchhoff's law true?

I mean why does the potential have to reach zero on reaching + terminal I know that should be intuitive, but what makes me confused that the path of gaining the potential which is inside inside the battery ( from + to - ) is different from the path of consuming the potential which will be any way outside the battery from negative to positive, it is intuitive if we are talking about potential gained by gravity for An example when we throw a ball upwards gaining potential it will take the same path on consuming it so all the potential must change to kinetic but this is unlike electric potential where it gains potential in a path and consumes it in stotally different one !