Do you know what gymnastics is? It's doing a bunch of flips & tumbles to get from point A to point B instead of just walking there, sometimes going the opposite direction and ending up back where you started, or in a completely different place.
Mental gymnastics is when you read something that's pretty straightforward but your brain goes & unravels it & turns it inside out & upside down & comes up with an entirely different idea than what was presented. Sometimes it's necessary to do that which is called critical thinking, but sometimes it's unnecessary to do that and that's what you did here. Because everything I said was straightforward, I am not creative enough to tell lies.
I was just using a quick easy term that you're all familiar with. Though Im pretty sure the word "fap" is an onomatopoeia for the rhythmic fleshy smacking noise of penis being furiously stroked in one's own hand.