" A securely attached child will store an internal working model of a responsive, loving, reliable care-giver, and of a self that is worthy of love and attention and will bring these assumptions to bear on all other relationships. Conversely, an insecurely attached child may view the world as a dangerous place in which other people are to be treated with great caution, and see himself as ineffective and unworthy of love. These assumptions are relatively stable and enduring: those built up in the early years of life are particularly persistent and unlikely to be modified by subsequent experience. "

― , John Bowlby and Attachment Theory