As I understand things, the soul is that small spark of Fred (or God, the Goddess, the Universe, the Great Spirit, Brahma, or whatever term you want to insert here) that comes to the physical world to exist (the Causal Body, the "cause of life"). As it does, it becomes more dense, attracting to it mental energy and forming abstract thoughts (the Mental Body), feelings, emotions and lower thoughts (the Astral Body), and finally solidifies into the Physical Body (and the Etheric Double).
Now, it has to spend time to gain awareness and control over the bodies, which explains why we are not instantly born with perfect knowledge of our higher self. Each body also has it's own consciousness. Newborns and young children are learning about their physical bodies. Then, they learn emotions and lower thought processes. Unfortunately, most of humanity never get's beyond this stage. Some do make it to more abstract thought, and a very fiew truely let the Causal Body, the Divine Spark if you will, to shine forth through themselves. Most refuse to let it, because the lower ego refuses to become subservient to the higher will.
Obviously, who you are consciously is not who your higher self is. If you put on a business suit and go to a corporate meeting you are obviously going to be different than if you put on a swimsuit and go to the beach. You don't act the same, talk the same or think the same. In a similar manner, my soul is currently wearing it's Shawn suit, just like your soul is now wearing you. Therefore, I am only my soul acting in the way that is appropriate to its lower bodies.
As always, this is just my opinion and understanding. Feel free to have your own.
As a side note, another theory I heard once is that there is only one soul. Since time and space does not exist for it, it comes back to this existence, sometimes in the future, sometimes in the past, sometimes right now, to experience different lives. This soul is you, me, him, her, my cat, that bird, the rock outside my front door, the Sun, far away planets... You get the picture. This one makes you think "Why was I so mean to myself?"