Why can't we remember what the ball did until it hits the pocket.

I know I used to struggle with this for years. It took me a long time to learn and pay attention to the entire ball path.. I would see the exact same thing with many bowlers that I have coached. I knew of some bowlers couldn't even tell me what pin the ball hit first. I would get that blank stare. 

Why is it so hard to remember? Is there something in our genetic makeup that causes this.

I don't really understand OP, I'm always watching ball motion from the arrows through the breakpoint and into the pocket.  How else would you know how to adjust?

For a lot of bowlers, what they see at this moment isn't reality.  They are readjusting their eyes or falling off their shot or who knows.  If you are having trouble reading your reaction, you should have someone else watch your shot.  Once lined up, use what you see as confirmation if you are doing what you want within whatever deviation you have.

All I can really add is what I personally do.  When I get on the approach and set my feet, I identify my target at the arrows and then look at my break point.  I visually draw my break point back to the arrows and then go (I'm visualizing my ball path).  I'll pick up the ball rolling as it crosses my mark at the arrows and then follow the ball the rest of the way trying to see what it's doing front-to-back, where it locates down lane and finally how it hits the pocket and leaves the pin deck.