Are you a comic book collector? I was reading Batman comics in the early 1950s, which I'm pretty sure was a few decades before you were born, and even those weren't anywhere near the first couple of issues. He got his own comic book in 1940.
Dad was a comic book nerd. I never really got much into comic books themselves, but I grew up with all the characters because he liked to talk about them. I did read some of the tattered books that survived his childhood and made it to the trailer (Like the original Sargent Fury books) Most of those are gone now. However, I still have many actual books about comic books that were his (and many that I read or at least skimmed while growing up) including one I bought him while he was in the hospital (The Ultimate Marvel Encyclopedia) because he loved reading about comic books too.
Hell, I have the 45 for the Merry Marvel Marching Society sitting on my printer right now. His membership card is the box with pictures and other paper memento's.
There are a few subjects that I know very well despite the fact that I'm not old enough to have actually participated because of him. The history of comic books is one of them.
Anyway, there are several interviews with Bob Kane that discuss the origins of Batman. You can find them on Youtube.