201: Accessing the subconscious, Depression from illness, Brain maturity

Today's questions: 1. Is it true that there are parts of the mind that we don't have access to, like a "subconscious?" Put another way, is there any information in our mind that we cannot reach down and consider with our conscious thinking? Some neuroscientists talk about thoughts as if they are served up to our awareness. But it seems like we can "direct" our thoughts. But can we "access" all the information and ideas that are in the darker corners of our brain's file cabinets? 2. You mentioned in episode 2 that people can also get depressed about their personal survival, like in the case of discovering they have cancer, but you didn't elaborate on what purpose that might serve evolutionarily. People in the Stone age wouldn't have known they had terminal cancer, but they might have a good sense that a disease or wound was almost certainly going to fester and kill them... What are the genes telling this person to do and why?  As a follow up, once a person can accept their impending death with certainty, should the depressive feelings decrease or end? Do people who embrace their mortality find relief and the ability to enjoy their remaining time relatively stress-free? 3. Why do human brains take so long to mature to competence? Yes we are born relatively early to accommodate the size of the head, but it's not a matter of a few more months. No other animal is so helpless for so many years. Are human brains slow to mature because they are so adaptable, so they hold off on forming synapses right away? Or is it because they simply have so many neurons to wire up in more complex ways compared to other animals, it truly takes that long? If the former, what is it about human intelligence that is so much slower to wire up if it's all hard-coded by the DNA anyway, and what advantage is there in postponing the ability to walk etc for so long?