The line comes from Shenmue, the 1999 Dreamcast adventure game where Ryo Hazuki investigates his father's murder. During the search, Ryo repeatedly asks strangers about sailors while looking for work and clues at the harbor, and that earnest repetition turned the exchange into a lasting joke among fans. Clips of the dialogue spread through forums, YouTube edits, and soundboards, where the let me guess sailors phrasing became shorthand for spotting an obvious lead. It remains popular because the delivery sounds completely serious in almost any situation.