A life well lived is a life that includes introspection. A life that is unaware of itself is an animal's life...actually only the lowest orders of animals are unaware of themselves...hell, even that is an assumption, we don't know for a fact that a worm isn't aware of itself at some level. Worms feel pain, that is some level of awareness isn't it?
For humans a life without at least some introspection would seem to be impossible, and yet I've met folks that seemed totally unaware of themselves. Or perhaps they had cultivated a life style complete with a revered disregard for introspection. There is no limits to what the human mind is capable of believing, so it is possible I guess.
The thing about fishing is that I can't imagine a person fishing without being introspective at some point during the act of fishing. Not necessarily a complete immersion in introspection the entire time fishing, but at least occasional brief bouts of it. For me introspection and fishing are too intertwined to be able to separate.
Perhaps it is the long moments of stillness while surrounded by nature that creates a heightened awareness of self. A lack of distraction is a state that humans avoid assiduously, that's why solitary confinement is considered a dire form of punishment. What person have you known that sought out a complete and utter lack of distraction? Meditators comes to mind, and yet they mostly meditate in relatively short durations. The ones who are capable of meditating for long periods of time are considered advanced masters.
Come to think of it, fishing is a lot like meditation, and the advanced long duration meditation at that. Say you are fishing, the only noise is natural sounds like birds and running water and wind in the trees. You are physically still, sitting without much motion, without talking, without actively doing anything other than watching your line. Meditators do that, they focus on a mantra the way a fisherman focuses on his line, and other than that you pretty much can't tell them apart.
So perhaps fishermen are advanced masters at meditation. Perhaps fishing is simply a form of meditation. Perhaps you and I fish, not for the fish, but for the peaceful solitude and stillness. Perhaps we fish so that our minds can become quiet and still, and gain a rest from the wearying world. Perhaps we fish so that we can have long quiet periods interspersed with deep thoughts about the quality of our lives, and how to improve that quality.
Perhaps we are not fishing to catch fish, perhaps we are fishing to catch insights, and mental rest.