You cannot choose what happened in the past.
You cannot control what choices made by people before you.
You cannot do anything for things labeled as 'past'.
Sometimes, out of your control, you are bound to the consequences of mistakes from people before you.
Sometimes it drags you down, makes you desperately in need to blame people before you for everything.
Keep in mind that past does not matter to the future.
Keep in mind that future is pure, untouched and ready for you to shape.
Whatever things left from the past which bind you down, no matter how much drive you feel to blame, keep in mind that everything happens for a reason.
Then, keep moving forward.