I wanna be a pet goldfish when I grow up

Fish(es?) actually can see you. Like they don´t have to have so complex eyes as we do, but they see you behind the glass and they feel that something is going to happen (if you don´t have one of those terrible rounded plain uncovered aquariums) and by the experience they are gaining they usually know, when you are going to give them food and when not.

And it's a surprise EVERY time.

RAINING FOOD.