Here's my theory, and strictly theory it is...

I know I dont scout as much as I used to. I used to not care where I went when I was younger and would scout every nook and cranny. Now I have a good idea of what's there and typically don't go into places I used to not go (bedding areas) and just leave em be. Looking back, I remember a lot of close gathered rubs, but had no idea what a 'core area' was or that hmmm this may be his bedroom. So now I dont see as many as I did because I try to stay out of areas that Im not going to hunt.