I am dead and alive.
I am not a zombie nor a cat.
You can bring me back to life,
or just let me die.
Everything depends just on you.
Who am I?
EDIT: As it seems that the answer could be broad, lets remark that "everything depends on you", so that when I say that "you just let me die" I mean that I don´t exist anymore.
I am not alive or dead until you can or can not think on me, the time you can I would exist, the time you can not I won't exist anymore.
Can not think on me = can not remember me.