I don't think I'm in a simulation, and I only just now reading this became able to verbalize why that is.

I reject as a premise any arguments that rely on some kind of 'probability that I find myself as me'.The reason for this is that I don't think that such probabilities can be considered to exist. You may say that I could have been born a hunter-gatherer thousands of years ago, some guy living in the future, or some guy living in a simulation in the future, but I don't think that these really work as potentialities. The hunter-gatherer's experiences are different than mine, as are those of the future people. I am myself, and am a unique structure that has unique experiences. My 'consciousness' is what it's like to occupy this particular area of spacetime. The hunter-gatherer, future man, and simulation man have their own consciousness, but they are different than mine. In some ways it works to talk about these entities with similar structures as a class (people), but I don't think it works in the way some people think it does. People aren't electrons. Each individual is different, and thus the descriptor is only a classification to generalize about some general pattern that keeps coming up.

Basically, they all either exist or don't, so it's not like I should be surprised to find myself as myself. Everyone finds themself as themself.

And I also tend not to take argumentation as strong evidence for anything, because above all it has a lot of problems of interpretation. Sure it may sound convincing, but how do we know there isn't some flaw in the reasoning that we don't see? For everyday things, it's not such a big issue, but when we start going into things positing the existence of entire universes, I think it's gone far beyond the domain where it can be reliable. The fundamental assumptions we're making that we don't know we're making start to pile up and matter a lot. For example, imagine trying to argue about time before the concept of relativity had been imagined? Zeno's paradoxes before calculus? You're just not playing with the right deck, and a lot of the time you won't even realize it.

This problem is still pretty huge with empirical information, but there it seems a lot more manageable (read: sometimes, it's POSSIBLE to manage it).