Basically, nothing would change on the outside but you now have the knowledge that you're completely alone in the universe. How would this affect you, if at all?
>what would you do if everything was the same except everyone is a psychological zombie but that doesn't affect anything so everything is still the same?
Low IQ. Everyone would still act the same, you would just be armed with the knowledge that they are just robots or NPCs. Women would still be programmed to be disgusted by your incel stench.
You ask like I've never thought of that already. Ever since I was a little kid I've had thoughts like "what if every other person around me Is just a robot and I am the only living person here?" I've had these thoughts since forever. And looking down at it right now, I'd say nothing would change. Right, I am the main character now, cool, like I wasn't a main character of my own story already, whatever, let's move on.