I was raised in a severely abusive household so I was never confident in my own abilities, however I was mentally strong..I had to be or I would never have survived.
I married and divorced young and became a single parent for 20 years with no help or support from either my ex husband or my family..that was difficult, I had very little money, and it was important that I got it right raising my daughter, and so again the steel backbone someone mentioned before came into play. She became an uber confident successful woman
I married again 14 years ago...mistake..I should never have done that..and out of all my life experiences and struggles this marriage has been the one that has systematically destroyed any confidence I may have built up..
I won't go into details as to the why and wherefores, but suffice to say because of that, I am much less mentally strong, than ever in my life..