Alright, so far our… honestly rather Dorky MC has, while not a clear, a very narrow picture of who they were. They were clearly some kind of vigilante or bounty hunter of some kind. Likely going after those who have been scavenging Eggman tech. Likely has blood on his hand and did that very thing for a while before losing his memory. clearly got betrayed by someone before losing his memory, maybe even was a scavenger himself, which would explain the gun and box…even this is just guessing though. Either way his past is truly messy and likely someone his current self would hate, or at the very least should do time.