I'll go you one better: Prove that anything whatsoever exists in anything other than your imagination.
"[T]here may be some other faculty [of my mind] not yet fully known to me, which produces these ideas without any assistance from external things; this is, after all, just how I have always thought ideas are produced in me when I am dreaming... it is not reliable judgement but merely some blind impulse that has made me believe up till now that there exist things distinct from myself which transmit to me ideas or images of themselves through the sense organs or in some other way..."[E]very sensory experience I have ever thought I was having while awake I can also think of myself as sometimes having while asleep; and since I do not believe that what I seem to perceive in sleep comes from things located outside me, I did not see why I should be any more inclined to believe this of what I think I perceive while awake. (Descartes, Meditations, 3 [7:39-40], 6 [7:77])
To sum up: you can't "prove" that anything exists except yourself.
With all due respect, Clemenza -- are you bad enough to take your materialist skepticism all the way as René Descartes did? Are you ready to doubt everything that cannot be "proven" to exist? Hee hee. Go ahead. I dare you. But if you do, "Be careful. You may not like what you find" ("Dr. Zaius", Planet of the Apes [Rod Serling, 1968]).
Je pense, donc je suis. It's not just a good idea -- it's the law.
"...the word 'I' is grammatically convenient, but does not describe a datum."
- Bertrand Russell
Better still:
I stopped thinking ther--......