According to some researchers, it is theoretically possible that we are living in a 2D reality, having out interpretations made into 3 dimensions by our brains. This is some pretty heavy, and intense information to digest – so if you want to do some more reading on it – So I wouldn’t suggest it while you’re tired.
In a recent lecture, UC Berkeley physics professor, Raphael Bousso tries to "break down the mysteries of the universe with a concept called the holographic principle."
In an interview, Bousso stated, "There’s a real conflict between the way that we’re thinking about the world right now, which is a very local way where everything happens independently in different regions of space and the way that we’re going to have to think about it,".
Here are some additional links.