The physiology of our brains has an impact upon how we think, when we think and how deeply we think.
Conservation of Energy
The brain is the human organ that uses the most energy and the more deeply we think the more energy it uses. Neuroscientists have discovered that we will limit the level to which we think about something to regulate the amount of energy usage of our brains. We may have all experienced the situation where we are hungry and can no longer concentrate, or we are thinking hard about something and our minds start to wander. It is likely that in these sort of circumstances our brains are limiting our cognitive effort to reduce its energy usage. So we tend to only think about things to a level we can get away with. One of the few exceptions to this is academics who are professional thinkers, rather like cognitive athletes and over many years have trained there minds to allow greater energy usage. I have often wondered if this is why many of the greatest intellectuals seem to have little interest in significant physical activities. So to have a more objective view of reality requires us to consciously think harder and this takes time, effort, technique and knowledge.