To be more precise, we are in all of them, but our consciousness only perceives one of them.

So the real problem isn't in quantum mechanics, it's in what the hell consciousness is and why it works the way it does.

However, note that you can have observations performed by a computer which e.g. counts events, and the counter will exist in all "worlds" (branches of the universal wave function, really), while each incarnation of it only "perceives" one such "world". So the physics works just fine even while we don't fully understand consciousness.

Why is it necessary for consiousness to be any different from that computer counter? It seems to me that the paradoxical idea is not quantum mechanics, but rather conciousness.

I actually agree with you. If you can accept that consciousness is basically a computer, then there isn't really anything mysterious going on. I probably could have phrased that better.