We call this phenomenon "quantum learning." Don't know if that is the right term for it or not, but there is no other emotionally resonant way to describe just how shocking/jarring the phenomenon is.
She has always been like this. It's how she learned to walk, to talk, to ride a bicycle, tie, her shoes, to read, etc. etc.
DS3.5 has passed through enough milestones that I'm starting to think his path is something similar, but with a warning tell. It's usually an early and short-lived manifestation of a new skill, followed by a seemingly fallow period of internal stealth testing with no apparent outward progress, then full (?) proficiency revealed. It's like he's excited at the idea of a new skill/interest and experiences emotional leakages of enthusiasm, but he wants to perfect "it" in his head before the big reveal.
