If I (my higher brain) do not intervene and manage the process, my primitive brain will provide a plentiful flow of almost randomly associated thoughts in its attempt to protect me from what it sees as threats (it fails to differentiate between potential and real). The primitive mechanical brain does its key job of protection very, very, very well, but a lousy job at creating happiness (though it will mechanically respond positively to certain pleasures).
One essential bit of knowledge is for a person to know who he/she actually is. We naively misconstrue this.
Who you really are is that which does not depend on changing contents or conditions. Obviously, if an entity can "have" something, that entity is not that - it is not what it has - it only has it. You have a brain and a body, that changes over time, but of course one can see how that might be counted as an integral part of "me", though it is actually merely a support system (without which I cannot survive, of course!). Who I am, nonmystically and literally, is that which experiences and is able to be conscious of myself as a thinking entity - I am my capacity to experience and think at the highest level. I am a viewing point for my life. I see what my monkeys running around in my brain say and do, but I am not they. I am he/she who sees it.
If you're not careful, you'll find yourself giving this some kind of mystical, magical meaning or see it as woo-woo. So it is imperative that you think it all the way through, as this is a key underpinning for all of life.