"Morris the Explainer" is the name my wife gives to the character, prominent in many poorly-written movies or novels, whose job it is to insert background information (thinly disguised as dialogue) into the story. And "Mark the Explainer" is one of my dominant personæ --- pretty obviously, given the half-million or so words piled up in ^zhurnal posts here during the past half-decade, eh?
Running comrade Steve (aka "Coach") wants to do the Tussey Mountainback  fifty miler with me this autumn. Steve is fast, an experienced marathoner, in far better shape than I am. He swears, however, that he'll stick with me no matter how slowly I go. I figure that if (a big "if") I can survive the distance it will take me ~13 hours.
So what should I do when I feel a need for more "personal space" in the middle of the Pennsylvania woods? Or suppose I get bored and wish that time would fly more quickly? My Secret Plan, as I've already told Steve, is to explain Hawking radiation and information theory to him. That will require some background lectures on quantum mechanics and general relativity, of course, to set the stage. (My understanding of these topics is rather chaotic, but that won't stop me.)
The hours will pass as if they were as many minutes --- for me, that is. From a listener's perspective the effect will be reversed ...