You spent weeks grinding LeetCode, memorizing every algorithm from bubble sort to Dijkstra's, and now the interviewer hits you with "explain sync.Pool's internal implementation and its GC interactions." Meanwhile, your brain is frantically searching for anything beyond "it's... uh... a pool... of things... that syncs?" The gap between what you studied (reversing linked lists for the 47th time) and what they're actually asking about (Go's concurrency primitives internals) is wider than the Grand Canyon. Classic interview experience: prepare for algorithms, get quizzed on obscure runtime implementation details that you've never needed to know because the documentation exists.