I was trying to show in a simple way why I think it makes sense for a simple lifeform to get more complicated.
Of course the simple think isn't thinking: Hey, I could use some hands, lets evolve them!
But by variation and natural selection, the creatures that did get something usefull like hands, will be more attractive and will get more offspring with this usefull thing.
So they are making the species more complicated.
I hope you understand me now, otherwise just ask.