Your...life may be of no consequence to anyone else but is invaluable to you because it's the only one you've got. Exactly the same is true of each individual deer, hare, rabbit, fox, fish, pheasant and butterfly.
A Latin expression that means "seize the day." Carpe diem poems urge the reader (or the person to whom they are addressed) to live for today and enjoy the pleasures of the moment. A famous carpe diem poem by Robert Herrick begins "Gather ye rosebuds while ye may…"