Let us formalize this idea. Let us take the space of all possible configurations. If you start from the pink region, for some unknown reason (we don’t know who put the molecules in the pink region), but if you start and you let the system run it would move out of that region, into the blue region. If you wait longer the universe will pass through every possible state.
Many times (just statistically) it would wander around in space of all possible configurations, every now and then passing through the blue region without getting through the pink region. The pink region almost has zero probability. The blue region is bigger, technically it has more entropy. The white region is biggest of all.
When the space is in blue region, people can exist, planets can exist. But when it does so, most of the times it does not pass through the pink region. That means most of the times (almost all of the times) if you find yourself in a world , more or less similar to ours, the past history does not looks like what you would have expected, namely all the molecules coming out of the corner of the box. In fact, you might find yourself in a universe (this is a universe born out of random fluctuations, just by accident the universe formed).
But this is not correct as well. Most of the times that universe is not going to look like what you would have expected in an ordinary theory where the molecules flowed out of the corner of the room. Most of the universes that are created out of fluctuations don’t look recognizable. They have properties that don’t make sense. They might look like anything as they would look like a bunch of galaxies.
Only the first time the Big Bang occurred it would look like something recognizable. Most of the times it would seem like random garbage, garbage good enough for us to live in. Now that’s crazy. Well we have a modern version of it. You ask the question, what is the most likely thing, the most likely configuration that would form out of chaos. The most likely, given that it has to have intelligence so that it can ask about it.
Well the answer is that the most likely thing would be one brain and nothing else. Because to make two brains is much less probable than to make one brain out of chaos. Physicists these days call it a Boltzmann brain and of course this is not the right theory of the world. We do not live in a where there is only one brain.
Wouldn’t it be better to have a one-shot world? A one-shot world means the molecules come out of the corner of the room, they do their thing and then they go off and we never hear about them again. No possibility of recurrences going on and on and telling us that the most likely thing in the world would be a single Boltzmann brain.
We would still have a problem. We would have to explain; why they started in a special configuration.