What happened?

What happened to me?
What happened to my critical thinking? What happened to my questioning and doubting everything?
How did I get to grow up old and stupid in...a year?
Why does everything seems so trivial, so clear, why am I acting like my parents?
I am not like my parents, I actually hate this part of my parents.
Why?
I don't care much anymore, I used to fight for the smallest idea I believed in. Now I just look, and smile.
I don't bother anymore, I used to cry, to yell, to make a mess, make myself heard.
I became so disinterested in people, in others...
I used to love people, I wanted people to know what I know, I wanted others to learn what I learned.
Now, I got my truth, I don't care about whther others get it or not.
What happened to me?
Why am I so disinterested?
Why am I so careless?
Everyone has the potential to change the world, but I lost all interest of even trying.
I was ambitious a year ago, I wanted this , that and that and all of that too.
Now I want nothing, I want to go through my life, that is it.
I wanted to be the best, not for the sake of being the best, not out of narcissism, it is just that leading is the way to pass the knowlege and the ideas to others.
Now, my ambitions are to work and get a check, raise a family and be simple-happy.
What just happened to me? Where did I fall and hit my head? Why doesn't it even hurt?
I miss my old self, I miss my excitement about life, I miss being ambitious, I miss not having inner peace!