Let's see. I've got some time, so let's find out if there's a documentary I haven't seen yet about a band I've followed for over 40 years. Granted, I've read multiple books about this band, seen countless documentaries and interviews, and heard their music repeatedly.
Ah! Here's a documentary on them I haven't seen. Undoubtedly, it will cover the group's history, which I already know by heart. It'll also likely spell out the reasons for various personnel and musical genre changes over the years, which I've also heard about many times. There's a strong chance it will also include highlights from the band's concerts--all culled from the same sources other documentary producers have used.
It should be an enlightening morning of hearing the band members and a narrator tell me about pivotal events in the band's history that I already know.
I might as well be reading a favorite bedtime story.