LOL...I thought old folks went to bed early?

An exclamation of enthusiasm or encouragement, as in You've said it really wellright on! This interjection has a disputed origin. Some believe it comes from African-American slang (it was recorded in Odum and Johnson's The Negro and His Songs, 1925); others feel it is a shortening of right on target, used by military airmen, or right on cue, theatrical slang for saying the right lines at the right time. [Slang; first half of 1900s]