I didn't really understand exactly what had happened on the first timeline

However, I was watching an old movie which is "Wargames(1983) and realized how the doomsday weapons went off. When President Bush on the first timeline was angry when he received the message it triggered somehow a computer automated response either in the U.S., or Russia, or China or England, or France or Germany or Pakistan maybe. And when this computer automated response (like in Wargames) got loose it set off a chain reaction that could not be stopped in all the nuclear armed countries on earth.

So, by watching Wargames(1983) tonight I finally understood how 5 billion people died on the first timeline and understood why people from that timeline helped create the 2nd timeline we all live on right now.

Because when President Bush read "My Pet Goat" to the children instead of getting demonstratedly upset it changed it to the 2nd timeline where the Doomsday weapons were not automatically set off by one of the nuclear armed countries on earth which then caused 5 billion or more people to die within the first month and civilization to end basically until around 6000 AD here on earth. 

So, we all didn't have to experience that. However, some people remember this in their dreams or nightmares or visions because somehow they remember what happened to some degree on the first timeline still. I'm not exactly sure how all this works I just know it's true.