Just a saying of no origin known
When someone is freaking out you say to them, "Simmer down Sampson"
Man, I need to fuckin’ simmer down! Simmer right the fuck down!
When ones attitude or tone is getting hostile or angry, About to reach boiling point. A person needs their teapot of an attitude to simmer down before reaching boiling point.
When Wesley comes at me all crazy with his tone, I tell him simmer down teapot.