...she can sort of intuit the hand gestures she'd need to use to start any given spell she focuses on, they do have things that feel like starts and ends and shapes where your fingers could match the startingplaces.

Merrin's memory for How To Operate Hypothetical Alien Machinery After One Demonstration is good enough that she can take a guess at which of her four orisons is Detect Magic.

...she can sort of intuit the hand gestures she'd need to use to start any given spell she focuses on, they do have things that feel like starts and ends and shapes where your fingers could match the startingplaces.

Merrin's memory for How To Operate Hypothetical Alien Machinery After One Demonstration is good enough that she can take a guess at which of her four orisons is Detect Magic, based on where the cleric's fingers were.