Even though the phrase was probably coined way back in 1916, the concept of "paying it forward" still occasionally appears in the news. It means that when someone does something nice for you, you in turn pass it along by doing something nice for someone else. It forms a chain of good deeds from person to person.
Music is like this in many ways.
We learn a particular technique from one person and teach it to someone else. We absorb the rhythmic beat from a great player we've jammed with and a year later, a younger player absorbs it from us.
And it works with musical pieces as well. The chord progression we spend so much time practicing in one tune becomes easy for us to play when we see it in another tune. Or we struggle to learn a Bach fugue in the key of F# but later realize that a Blues in F# surprisingly seems natural.
Go ahead... pay it forward.
Pay it forward from musician to musician, from song to song, and from yourself today to your musical self tomorrow.