The Hydrozoan, a small predatory sea creature like a jellyfish but without all their well known exciting higher functions, can achieve the dream of millions and become a child again. When adverse environmental conditions threaten death it can collapse into a rugged blob of cells to survive. When it re-emerges, it does so as a child – literally building itself up all over again. Since this isn’t just a shell to hide in, but a complete structural restart, it seems possible that it could keep this up forever.