In Super Mario Bros. 2 if you pause the game
Then press Up + A + B on controller 2, then unpause, your life is over.
And you might be thinking to yourself, "That's stupid, why would I want to do that?"
Well, let's suppose that you were playing stage 5-2 (the one where you have to ride an Albatoss or Beezo across a giant pit)
And at the end you're feeling silly and you run and jump up on the Mask Gate before it opens.
And just like that, you're stuck in a wall.
There are only two ways out, sacrificing one of your extra lives or resetting your NES.
Guess which one I recommend?