Modern motivational speakers constantly sell the illusion that "you can change everything" if you just think positively. Dr. Sharma brings us back to spiritual reality.
There are certain Karmic events (Prarabdha Karma) that are fixed. You cannot change them. Even Lord Ram, the supreme avatar of the Divine, had to suffer the pain of separation from Goddess Sita. He did not use his divine powers to "change" the situation instantly; he accepted the pain and walked the difficult path to rescue her.
Stop fighting the unchangeable past. Accept your Karma, feel the pain, and keep moving forward. That is true spiritual strength.