With any relationship as time goes on people come to the point where the "Thrill is Gone" or become Jaded so to speek. Where the hobby is not a relationship with a specific individual persay it is a relationship in spirit between one person and many other individuals they have choosen to engage personally with.
I would imagine that most dawgs that find the hobby in the begining feel like a kid in a candy shop. They never imagined there was this many beautiful women of all colors, creeds, and talents just a phone call away. Everytime they look they see a young hottie just like the girl next door, or a girl that reminds them of someone they always fantisized about, but just like the first time they saw their hot girlfriend or SO, and thought to themselves nothin could be better than this, eventually the relationship cooled and you began looking somewhere else.
So the question is, as time goes on and you experience the hobby more and more fulfilling all of the fantasies you once thought were only dreams, are you losing the thrill the hobby gave you in the beginning are you becoming more jaded towards sex in general, do you find yourself turning the page on providers you once considered your ATF, because you know its there for the taking when ever you want it just like the wife or your girlfriend?