Life is the opposite of death, like motion is the opposite of stillness. So life is all about doing, so it's all about optimizing a function that as humans we call " utility ", which is the mesurement of the capacity to do with efficiency.
* why do other people act like that? Because it's useful for them. * why do we see that bacteria motion/behaviour? Because it's useful for her. * why do a big forest fire is sad? Because it brings stillness where motion was. * etc...
