be young at heart

be young at heart

To behave in a way or have a disposition that is more youthful than one's age. Grandma is still so young at heart—I can't believe she's taking dance lessons at 90 years old!See also: heart, young

be, stay, etc. young at ˈheart

(of an old person) still feel and behave like a young person: He says that the secret of living to 100 is to remain young at heart.See also: heart, young