You might not know that an average cumulus cloud weighs over 1.1 million pounds. Despite its fluffy appearance, the water droplets inside are heavy, but the cloud floats because the dry air beneath it is even denser.
There is a species of jellyfish called Turritopsis dohrnii that is biologically immortal. When stressed or damaged, it can revert from its adult medusa stage back to a juvenile polyp stage, effectively restarting its life cycle. While they can still be eaten by predators or succumb to disease, they do not die from aging.
Consider this: Your brain produces enough electrical energy to illuminate a small light bulb. On average, it generates between 12 and 25 watts. This power drives every thought, sensation, and movement you experience.