One of the things worth thinking about is the idea of what we think of as a fish "thriving."
It lives a week and dies, and we know it did not live long enough. A month, and we say, he was doing so well and then what happened??? A few months, and we go nuts checking parameters. A year and we say, "hey - he had a good life."
This is sad.
A day, a week, and it was probably stressed out from the trip to your home from the ocean. You bought a fish on its last legs. Bad luck.
A month and he might have been slowly starving to death, slowly succumbing to some ailment he suffered thanks to being captured - and perhaps we hastened his death by not giving him a month to three in quarantine to recover. Perhaps he was so stressed out that he couldn't eat and then we didn't give it the food it wanted. Perhaps it ate enough to survive for a while, but it took so much energy to deal with all the strange new water parameters that it could not actually fend off whatever diseases and other fish challenged it in its new home.
A few months, and it becomes more our fault - it couldn't adjust to all the new parameters, we didn't feed it properly, we challenged it with other fish.... We are to blame, and while it is "just a fish," it is a living thing. It's not just art.
A year and it was still our fault. Most of the fish we choose to keep should be able to live years and years in our tanks. Some should outlive us if we are in our 40's or 50's when we buy them. Yes, there are some species whose in-the-wild lifespan is short, but most aquarium fishes live WAY longer than we typically keep them alive.
I know that there are some of us who buy difficult fish thinking we can keep them - and some of us really can - but most think we'll just get lucky. This makes me so very sad, and I hope that those of you who read this through to the end will agree that the only fish you should buy are those with the greatest possibility of surviving to some approximation of their natural lifespan in your tank.