When we incarnate we have to be reintroduced to the physical realm; we don't just slide from one plane into another knowing how to survive. Initially we rely completely on our caregiver(s) to look after our physical needs. While we can't yet function in the waking world, we're still very connected to the disembodied state. As parents tenderly watch their little ones sleep, they might wonder what the baby could possibly be dreaming about. In fact, the baby's Ka is fully aware and functioning perfectly in its disembodied state, exactly as it will for the child's entire life.
As time passes, the child sleeps less and less, separating from the disembodied state and taking its place in the conscious, physical state. Eventually the conscious mind will dominate, surrendering to the subconscious only during sleeping hours. There will be times in the early years that the child will function in both realms, not yet fully separated from its unconscious state. This explains why children sometimes talk about seeing people or things that we can't, as I described in my post of October 31, 2009. However, some children will not completely lose their ability to see 'spirits' or visions, they will retain that ability and become what we refer to as psychics.
As we function in the physical world, we're usually not aware on a conscious level of the goals and tasks we've set for ourselves in life or the circumstances we've agreed to participate in for the sake others. Remember that we're not here only for our own journey, but also as players in the journeys of many others. If we knew what life held in store for us, it would totally negate the purpose of the journey. It is not only imperative that we not know, it is a kindness. I know of many people who regularly seek to find out about their future by visiting psychics or using some type of divination such as tarot cards, tea leaves, palm reading, or what have you. While all of those things may be of passing interest, knowing what the future holds would almost certainly be detrimental to the journeyor.