The Jedi mind trick : for lack of better descriptions. Humans trick themselves into thinking there is more than there is by overcomplicating the issue. Hear me out below:

Okay, now the physics problem again.. why isn't there more than 3 dimensions? Technically it is the only dimension - and scientifically only 1 dimension exists, the math shows more than 200 dimensions, but engineers have only built ways to see that 1 dimension. Nature doesn't allow overlapping dimension, what you see is internal both by math, and psychology.