Goodness, I don't know what you've been reading! As far as the Sphinx is concerned it is believed to have been built by ancient Egyptians of the Old Kingdom during the reign of the Pharaoh Khafra approximately 2558–2532 BC ( add to that the 2014 years A.D. ) and you have and age of 4500 years. Amazing feat nevertheless. But NOT 15000 years.....Brain Surgery? None, of course ! Except if you include pulling the brain out through the nose in the mummification process....That could be called Brain Surgery, maybe ask your friend Van Daniken, his brain was almost certainly remove the same way..............Chris Dunn, another nutcase, has the theory that the Egyptians had access to ultrasonic work tools. Unfortunately, for his theory, not one trace or record of anything like he describes remains.
Oh My, I have wasted far too much time on your nonsense, Life's too short................................