Are you not in the world? Are you not apart of it. If you’ve changed yourself, you have literally changed the world and its inner workings in an a way that’s inconceivable. That’s why you don’t think you have changed the world yet. It’s like golf, if you hit the ball with a 1 centimeter of a difference, where the ball lands will be significantly different had you not made that small adjustment. So if you’re hesitant on making a change; you would be 1 centimeter away from having evolutionary impact.