The fear of life is the first cause of all our psychological troubles.
The fear of life is a silent and false assumption that life is untrustworthy and dangerous that runs in the background of all experience.
Now, strictly speaking, there is no requirement that you understand the cause of your mental misery before you can be rid of it and, conversely, mere understanding of the cause will not free you of it. But a clear understanding of the actual cause of our mental misery, although not required, vastly simplifies and mitigates the tumultuous experience of regeneration that often follows that first look.