Great question, I feel it does center around the self esteem and how we view ourselfs. I well remember the total feeling of just being empty of feelings devoid of and pride self worth. I took many years and a wonderful women to start to see myself differant. I was very luckly to have her support, this after she found me more dead than alive. I was convinced I had no purpose in this world. I think it all centers around how we were used and in my case beaten. We just did not have the ware with all to deal with it. As the twig is bent, so grows the tree.
it is and has been quite a trip thru life, as last I feel that I am in a better place, it takes work and in my case a wife the was and is forgiveing and helpful. At last a relationship has gone right, messed up three.