Life is a journey of ups and downs.. It's a game where you loose and win. Yet, it's up to you , the player, how are you going to play the game and the techniques of standing after a failure.
I guess the definition of life is "Energy".
Seeing as it is all around us. Giving us power to do whatever we want.
Life without energy is unthinkable. It could not exist.
Have a nice day.