Grey's Anatomy - Season 6 Episode 15 -

In his new role as Chief, Derek restores the hospital lecture series, and several attendings present to the group pivotal surgical cases from their pasts: Bailey reflects on how shy she was as an intern until getting advice from Webber, Callie looks back on a polio case, and Richard recalls a case in which he and Ellis worked on a patient diagnosed with AIDS, known in 1982 as GRID.