system
Given the following post, respond as if you're commenting on Reddit:
human
[FF7] ELI5 Cloud's true past and why he lied about it

Beat this amazing game for the first time today (I'm a little late, I know). I'm having trouble putting together Cloud's timeline starting from his childhood and growing up in Nibelheim with Tifa to the point where he arrives in Midgar and joins AVALANCHE. I know he lied about alot of things, but why exactly?
gpt
Cloud wasn't lying. His memories were messed up. Here's the order of events as they are explained in *Final Fantasy VII* (more details are given in *Crisis Core*). Note that the rest of this post is full of spoilers, so stop here if you don't want to know them.

Cloud grows up with Tifa in Nibelheim. When he gets old enough, he goes to Midgar with the intention of joining SOLDIER. However, he doesn't make it and ends up becoming a regular guard instead. He accompanies Zack and Sephiroth (both first-class members of SOLDIER) on a mission to Nibelheim, where the Nibelheim Incident occurs. Sephiroth goes crazy and burns down the city, Zack and Sephiroth fight, but it's eventually Cloud who defeats Sephiroth by throwing him into the Lifestream. Both Cloud and Zack are severely injured at this point. Their bodies are found by Hojo.

Hojo spends time experimenting on the two of them with Mako. Eventually, Zack becomes strong enough to break them out of the Mako vats that they're imprisoned in. Being a SOLDIER, Zack had already been exposed to Mako and handled it okay. However, Cloud began suffering from severe Mako poisoning. They hitch a ride back to Midgar, but some Shinra troops catch up to them and kill Zack. Thinking that Cloud is too far gone already, they just leave him to die. Cloud crawls to Zack's body and picks up his Buster Sword.

From this point, the Mako poisoning messes with Cloud's memory, so he believes that he was a first-class member of SOLDIER and was the one who accompanied Sephiroth to Nibelheim instead of Zack. He returns to Midgar and joins AVALANCHE to get revenge on Shinra. This is where the game begins. Cloud's memories don't get sorted out until midway through the game when he falls into the Lifestream and experiences Mako poisoning a second time. Tifa joins him and helps him sort things out.