[Stephen gets a good look, then. He flips back through the conversation in his mind -- anterograde amnesia explains the shifts from topic to topic, the changing stories, John's apparent failure to talk to Sherlock after his death. Clear enough that Sherlock's gone through this discovery before, likely with John on the other end of the phone line.

Shit.]

Breathe.

[He says it with all the authority he can muster.]

You've been through this before, you've left yourself notes. You're functioning, well enough I didn't catch it. Deep breaths, slow it down.