This is the Phil Och's song, "When I'm Gone." It's not his version, though, but an absolutely exquisite cover by two groups, Kim & Reggie Harris and Magpie. I first heard it years ago when the long-running Saturday night show, The Midnight Special on WMFT in Chicago played it as their closing song each week. They used it for a great many years, and as far as I know they still may be. I just haven't heard the ending of the broadcast in about five years. But they were still using it then.
My folks absolutely loved the song. Loved it. They enjoyed The Midnight Special, a great deal although they liked it more in its earlier years and not the selections as much in its (and their) later years. But they always listened and, if not always all the way through, they always made sure to listen to the ending, just to be sure to hear The Song.
The song is about all the things to do in life now, because this is your chance to see them through.