Warning! SPOILERS about Grey’s Anatomy season 21, episode 3 ahead. Meredith and Amelia’s Alzheimer’s research being in limbo refocused Amelia’s attention on a difficult surgery, mirroring and honoring one of Derek’s cases from Grey’s Anatomy season 6. Ever since Catherine and Meredith stopped talking about Amelia and Meredith’s Alzheimer’s research to tackle the lesions on …