Well, how about this, fish can learn

I was involved in a study once where hatchery coho smolts fresh out of the saltwater acclimation pond were put in an aquarium with a lingcod, who promptly ate most of them. The one's he didn't eat were marked and put in with another lingcod along with a bunch of "rookies". The rookies got et at many times the rate of the survivors. But we also put fish in the aquarium on another side of a porous plastic barrier that got to watch the lingcod at work. When they were put in with him the ling had a devil of a time catching them - that's right, they learned from watching their buds get eaten. :p

So at least coho are smart enough to figure life and death out, which is what is important to them anyway. You are right, CF, it's doubtful if most humans can even figure out what's important, period.