Take six cubes.
Arrange them into the shape of a crucifix.
Take two more cubes
stick them either side of the crucifix
at the point where the cross is made.
Now you have a tesseract.
A tesseract is a 3 dimensional object.
A tesseract is also a 4 dimensional object
a hypercube
unravelled.
A square unravels to a line.
2 dimensions unravel to one.
A cube unravels to a cross.
3 dimensions unravel to two.
A hypercube unravels to a tesseract.
4 dimensions unravel to three.
You exist in three spatial dimensions.
In the same way that a one dimensional person
could not visualise a 2 dimensional square,
or a 2 dimensional person could not visualise a 3 dimensional cube,
you cannot visualise a hypercube.
A hypercube is a thing you are not equipped to understand.
You can only understand the Tesseract.
You can see the thing unravelled
you cannot see the thing itself.