Thought experiment: Is my brain also generating reality without a physics engine and is filling in details that it thinks should be there? If true, what are the advantages/disadvantages of it?
A few times a year I might wake up in the middle of the night and — at first glance — perceive a goblin sitting on a nearby chair. As more of me wakes up, I realise it’s a pile of my clothes.
Now I’m learning German, I have the experience of listening to a conversation in German, thinking I’ve heard a particular word, asking the locals what it means, and finding neither of them noticed that word being used — but I genuinely hear the unspoken word, so I know a pre-conscious part of my mind is filtering all the German I hear through a vocabulary which is too small.
My mother has Alzheimer’s, and one of the bigger surprises was realising quite how many reality-models we have by way of her losing them at different times. When I was caring for her, star jumps terrified her, she forgot what windows look like at night and how to count past 5, and she lost both object permanence and the concept of left: https://kitsunesoftware.wordpress.com/2018/01/31/alzheimers/
One of the advantages of having a model of the world is it allows you to predict the future.
The only disadvantage I can think of is that it is comparable to branch prediction failure in a pipelined CPU — for example it can be very tempting to apply that to fellow minds, and when those minds don’t think like you, you can annoy them no end by telling them (implicitly or explicitly) that you know better than they do what they do and don’t want. Or you might become convinced that wearing lucky pants causes your sports team to win/your lottery numbers to come up. Or etc.
Don't tell me it never happened to you!
That was one of the weirdest experiences I think I've had.
Cut to a few hours later when they took a break and wanted a snack. So they went to their kitchen and tried to look in their real world fridge, and immediately slammed their head into the door as they tried to stick their head through it without thinking...
I have not actually had any incidents, but I have to consciously not crash into things, or drive wildly.
If you manage to not move your eye while paying attention to the finger, you'll find that it doesn't look quite right when you put it over the blind spot.
With your finger you know it should be there, so something finger-like fills the blind spot. If instead of a finger you try with something like a black dot, you'll see it disappear completely.