The line comes from Ace Ventura: Pet Detective, released in 1994, where Jim Carrey built the title character around broad physical comedy and instantly quotable catchphrases. Alrighty then became one of his signature sign-offs, repeated in the sequel and quoted by fans long after the film left cinemas. Its short length and instantly clear tone made it easy to lift into memes, reaction videos and soundboards, where it still works as shorthand for smug agreement, a plan coming together, or a character stepping confidently into chaos.