Picturing the dimensional structure of our own universe is fairly easy as I demonstrated with ten fingers.

Trying to imagine all of space and all the infinite number of multiverses expanding into 11 dimensional space as explained by string theory and having all of these universes co habituating the same space we are in but in different dimensions is damn hard to visualize.

It is said the concept of string theory came 200 years before we may be able to understand how it works.

Based on observation be it indirect or direct there is still a chance to understand the grand unified theory mystery of uniting large forces like gravity to the quantum universe.
I think there is still a clue in the math result of Einstein equations that when extrapolating them to quantum gravity they give a result of: infinity plus infinity plus infinity...for infinity.
Mathematicians claim the result to be nonsense and a total breakdown of physics that apply to the large observable universe.

The clue is that on small scales the fabric of space is so dynamic and random all results at once is a valid answer.

How small is the space fabric we are talking about?
if an atom were the size of a football stadium its proton would be a pin head and a quark is magnitude smaller than the proton.
Now imagine a billion billion billion times smaller than that and we are approaching the plank scale of ultimate smallness. The existence of anything this small in a world of fluctuating space time fabric would be like a particle ,if large, fluctuating like the planet Mercury jiggling back and forth to the orbit of Pluto and back.
WE HAVE MEASUED THE NAture OF QUANTUM SPACE, by seeing high energy large photons arriving 5 seconds before photons of low energy(small) because the small protons had a bumpier ride over the 7 billion years it took to get here. Just like large wheels have a smoother linear ride than tiny wheels go up and down al the time.

In short we can learn even from what other people consider to be a mathematical mistake. When an astrophysicist decides what to measure they still take a leap of faith in their imagination that they may reveal a fundamental truth. Their imagination is no more expansive than yours. Keep dreaming.