A bowl is a tiny, isolated environment starved of oxygen, which means even a slight change in the water chemistry can be lethal. I say this because goldfish pee with abandon. They unleash more ammonia than other aquarium fish, a toxin that would be diluted in a pond or a river but can kill a fish in a bowl. This is why, I would say to the woman, a bowl makes the conditions of living impossible. But when a goldfish manages to survive it, no one thinks of their feat as extraordinary.
