Realize that uy do not change the world per se; uy change uyr own personal perspective, which instantly shifts uy to a new, slightly altered parallel universe. The only way to change the future of a timeline in physical reality is to concurrently change the past. When the change in the past occurs during a moment uy decide you weren’t present for to be able to tell the difference, the alteration can occur seamlessly. This happens almost all of the time.