Stuff I've heard, stuff I've played, stuff I've remembered and stuff I've forgotten.

That's not a bad description.

"Stuff I've heard" often comes from old films on TV.
"Stuff I've played" often comes from sessions.
"Stuff I've remembered" may well be from the radio in the days of my youth.

Mostly, the above are only in outline form and the internet plays a large part in filling in the details. This is also where I am reminded of the "stuff I've forgotten".

DC