That's exactly what we think the case was before the Big Bang, I think, since points are zero-dimensional.
It's truly weird to imagine the Universe exploding from a point into a line, then into a planar region, and then into a three-dimensional domain.
All while not exploding and expanding out into anything else.
Or does it? How can you find evidence for a fourth spacial dimension? We could be living on a "bubble" of three-dimensional space as a fourth is filling in undetectable from us.
Is it possible to conceive of something of anything less than one dimension? If so, how? I'm thinking about the way that Carl Sagan used the tesseract to represent four dimensions.
You could have half a dimension, where things can only go one way. Like time.
I just imagine a pinprick of light emanating from a point. The place where light is only exiting, not entering, is a point with no dimensions.
But then it would have contained no information right?