I have learnt through the hard way that our reality is shaped by what goes on in the mind. I was ignorant of this fact until i learnt it the hard way confining me to crutches today.
Weeks before my accident, for some unknown reasons, i was entertaining the thought of being involved in a fatal accident. I complained to my brother who advised me against entertaining such thoughts...i however continued be i couldn't control the thought.
I was in his state of mind until i had a fatal accident, and i had to gibfir total hip replacement surgery. Today, i depend on crutches for mobility. This opened my eyes to powers of our minds
I have since learnt how to control what goes on in my thought.
So i believe in your theory of dream big for what you continuously thought about most of the time is what you will become.