The Butterfly Effect (2004)

Evan Treborn has lived his life differently than everyone else. Throughout his childhood, Evan experienced blackouts where he wouldn't remember what happened. He had memories of his childhood, but the blackouts would happen and he would no longer have a memory of what was happening. Most people didn't believe him about these blackouts; they assumed he was lying, and slowly he stopped having them. When he was in college, the blackouts started happening when he found old notebooks. He would go back and remember what happened in a blackout, and he slowly realized that these blackouts gave him a special power to affect the world in a way most people do not have the chance to. Evan decides whether to use the power to help himself or to help others.