Habitable Epoch of the Universe
 

tl;dr version:
About 10 million years after the big bang, during a time when single giant starts were forming basic elements (no galaxies or supernovas yet, but rocky planets would have been possible), the average temperature of the entire universe would have allowed liquid water to exist.

Meaning water, the most widely accepted prerequisite for life to form, would have been literally everywhere. Let your imagination ponder the implications of that.

More reading: here's a page of Google results. Take your pick.

Credit to Abraham Loeb, Astronomy Department, Harvard University.

the planet sized fish must have been cool

Water won't stay without an atmosphere unless it's frozen or encased.

Star Turtles.

All the way down?