@owlette
Have you ever heard of the butterfly effect or a ripple effect? The butterfly effect is often referred to when talking about timelines. Go back in time and even stepping on a butterfly that you didn’t before in the past could change everything in the present. Kind of like a ripple effect, it may affect something that may have happened.
Let’s say for example, that butterfly was the reason an argument stopped distracting a person and stopping them in their tracks before getting hit by a car. Now the butterfly is gone, they get hit and affects the people who knew the person.
So basically, even if they do small changes, it can change other things that didn’t happen before.