LIfe changing moments

Can you think of a moment in your life that was so life changing but it didn't seem like that at the time. Like it could of been a small little decision like going to the store or not doing a test for a class, or even just saying hi to someone. And because of this choice, this tiny little choice it completely changed your life. Like think about how your life would be if it wasn't for that moment. I am aware every action you do affects your life some small and some big, but im talking about a choice that has showed its relevance over and over throughout your life. But what about moments that were inevitable no matter what the circumstances were you know it was going to happen. An example could be meeting someone because of a friend but no matter what school you picked to go to you would of still met this person and forever affected your life. These are thoughts that have been intriguing me recently. These examples could be me or someone I know but I wont tell who.