Very wise words. They are neither complicated nor is their meaning complex, yet are difficult to understand for so many.
Sometimes it is easier to sit and stew in your own pity, anger, and frustration than it is to actually do something about the issue. Sometimes complaining masks itself as a fixer and makes you believe you are doing something about it, changing it. But complaining, blaming and avoiding only builds a life that creates more complaining, blaming and avoiding. Take ownership of yourself and the decisions you have or have not made because you own them. Some will say, "My mother or my father or my spouse, teacher, boss, friend, enemy blah, blah blah." Yep, they hurt you found your weaknesses and exploited them, but you choose how you react to those situations and how long you give your power to someone or something else. It's all you. Your life, your will and your feelings. So own it, step over it and run from it because the past can not hold you back and the future has not yet been written. Right now is what you can control so control it and get over it.