The Secret History of King Solomon & The Queen of Sheba with Ralph Ellis - Duration: 1:11:30. Russell Scott 434,840 views
From Wikipedia, the free encyclopedia.  Gonna Fly Now , also known as  Theme from Rocky , is the theme song from the movie Rocky, composed by Bill Conti with lyrics by Carol Connors and Ayn Robbins, and performed by DeEtta Little (the sister of actor Cleavon Little) and Nelson Pigford.
It is a reference to the theme song from Rocky III: The Eye of the Tiger by Survivor. [Wikipedia]. The song was an instant hit and is rooted in pop culture to this day. See lyrics for some context. Your hunch is right, though. It is about a feeling of confidence and power.