The Many Worlds Theory
This theory suggests that every decision decided, every choice chosen, and every path taken actually creates separate, parallel universes in which where there are crossroads, both roads are taken. Let's say that your friend comes to you and gives you a piece of candy. You keep the piece of candy to save for later, but then your sibling comes along and demands to have it. You have a choice: give the piece of candy or keep it yourself. Another great example is... yourself. By choosing to refuse to skip school, you have just created an alternate universe where you did skip school, thus losing the opportunity to learn about the multiverse. Although you made your choice, in a parallel universe, you will make the opposite decision of what you made in this universe. As you live your life and make your choice, actually in parallel universes, you made the same and opposite decisions that led you to explore different endings.