Person A, a dancer, learns as they practice in their apartment for a show that certain movements, when the mind is relaxed, can control the environment around them...kind of like an Airbender. [You can choose the element, obviously, this is just a suggestion!]

Person B, one of A's roommates, walks in on A practicing their superpower one day...but instead of being baffled, B smiles and declares: you are now ready.