If Sherlock wanted to rip his eyes off the stately progression of various neural frequencies, he would be physically incapable. It isn’t that they’re elegant and organic and mathematical and gorgeous and pure and human and divine. Though they are. It isn’t that they’re the closest scientific approximation to John’s thoughts he’s likely ever going to view. Though they’re that, as well. It isn’t even that he can see clear as day all the aggregated individual interactions and permutations between the billions of neurons living inside the skull of the man he loves so much that it hurts to look at him occasionally. That’s true too, but that isn’t what strikes Sherlock right through his core either. It’s that John said that he deserves privacy, and privacy means keeping some things hidden, and John has just invited Sherlock inside his head.

The detective feels as if he’s just crested the top of a roller coaster.

He is falling either:

1) in circles like a felled predator
2) to pieces
3) in on himself
4) through the dull grey floor
5) apart

or perhaps

6) in love

though that seems rather redundant at this juncture.