The line comes from The 7th Guest, the 1993 horror puzzle game set in a haunted mansion filled with notoriously difficult puzzles. The phrase fits the game's tone, where the host taunts players attempting brain-teasers that are harder than they appear. Clips from the game have long circulated among retro gaming fans on soundboard sites and forums. It endures because the wording is universally useful, working as a dry warning for any challenge, riddle, or trick that fools people at first glance.