Fish in a House

You named me once,
then forgot;
I don't blame you.
What is the point of naming a fish?

You dutifully feed me.
I should thank you, I guess.
No matter how cold the water.

Now and then,
I worry I'll outlive you.
This house is another water tanker,
you don't have any gills.

When night comes,
you dream and I dream too.
There I teach you how to swim,
how to live empty.