Old

In ancient Greek and Roman times, the average life expectancy of an individual was only 25 to 30 years. And if you were around in Great Britain in the 1800s and early 1900s, there’s a chance your 21st birthday gift would have been a visit to the dentist to have all your teeth removed and replaced with dentures.
If you were a type of jellyfish called Turritopsis dohrnii you wouldn't have to worry about getting old. When faced with environmental stress, like starvation or injury, this species can actually revert to an earlier stage in its development, almost like a butterfly turning back into a caterpillar, or a frog becoming a tadpole again. The Turritopsis dohrnii’s ability to switch back and forth between life stages means that, it may be the only known creature that can actually live forever. But who wants to be a jellyfish? It is in honor of Jim Kempkes birthday that our topic today is..Old!