The line comes from the opening of Half-Life, released by Valve in 1998, where physicist Gordon Freeman reports to the test chamber at the Black Mesa Research Facility. Scientists guide him through the early experiment in calm, procedural dialogue, just before the resonance cascade turns the routine test into a catastrophe. Clips of that pre-disaster banter later circulated on soundboards and in edited gameplay videos, where players isolate the polite instruction out of context. It stays popular because anyone who knows the game hears the warning hidden inside the politeness.