I remembered.
The 'butterfly effect' is, very shortly, the gigantic effects that the smallest of actions can bring. I'm not going into how it got it's name, you should already know.
But I must say I'm not the biggest fan of this effect when it comes to time travel. When it comes to time travel I believe, how do I say it, in 'alternative timelines'. Said simply, when you are given a 'yes' and 'no' question, the very timeline splits where in one you say 'yes' and in the other 'no', maybe even third one where you don't say anything, there can be literally infinite amount of splits that can happen in a single spot in time.
That's why I also don't completely believe in this theory, even though I believe this is the most correct one. It's too locigal for my taste.
That's why I believe it's a bit more 'simple'. Let's say a timetraveler travels back in time, instead of the timeline splitting into infinite amount of new timelines, it instead splits just twice, both times into two different timelines. The first split happens in the present. One where the timetraveler travels back in time, and one where he doesn't. The second split happens in the past, where the timetraveler travels to, or where he doesn't.
The difference between the 'original' 'alternative timeline' and my 'changed' 'alternative timeline' theories, is that one is more about free will, the other in destiny. In fact I'll write more about it in my next chapter, and by more I mean the destiny part.