well.....itz kinda simple i guess....

at first, your mental states work on instinct.....the mental states themselves have no knowledge of their meaning (thinking), but essentially, the body feels itz hungry, so the baby cries.....from this, comes empiricism....your mental states will essentially correspond one feeling (i.e. the body) into having meaning (i.e. the mind).....itz a simple system of going from instinct, to empiricism, to knowledge.....

now, most knowledge is derived from empiricism.....there are no "thoughts" programmed into your mind at birth....it all just starts to come.....once your mental states begin to grow and become more aware and mold to empirical understandings you rely on memories and such for a priori knowledge.....eventually, the physical attributes of the brain grow with the body, new functions perform, and from memory and empiricism, new thoughts are derived....

it is said a child doesn't actually have a fear of dying until around the age of 5......and that a child doesn't even comprehend that you have your own thoughts until around the age of 7.....

then, as a teenager, all sorts of whacky shit goes on in your brain and new things begin to happen.....the reason most people seem to fall in absolute desperate love, and often remember said love, is because the brain begins to cross new wires.....specifically that which is connected to the emotion of love....for girls, this usually happens around 14-15....for boys, around 16-17.......