Heraclitus is famous for his quote "No man ever steps in the same river twice." His philosophy captures the fact that both the river and the man are different. In my short time of fly fishing, I have experienced the same sense of newness every time I go to the river.
I have my favorite spots -- 11 Mile Canyon of course (only 50 minutes from my front door to first cast), and Deckers (the fishing is not as good but it was a childhood destination), and some places on the Arkansas up by Salida. The thing is, though, no two trips are alike. The flow may be higher. I may get to the river a little later in the day. I may try and fish longer with a dry even when few fish are rising -- just in the hope of drawing one to the surface. I always figure there has to a first fish to rise at some point, right? I may try an Amy's Ant. I don't fish the river twice the same way.
Maybe that's part of the appeal of flyfishing for me. Even as I get a little bit better, there's a new challenge or a new experience waiting every time I step off the bank and feel the current against my legs, feel the rod in my hand, and feel the hope with the first cast of the day.
Orvis 101 Introduction to Fly Fishing
Orvis 201 Streamside