Take a look at the audiobook for Moonwalking with Einstein. It's uh. There's a line about Bill Clinton copulating with a basketball; that may be a little out of bounds. By necessity, the author makes some touchy references to things.
It's an amusing book, but also a valuable summary of a huge body of knowledge that boils down to one important fact: the human mind, with all its variation, has fixed capabilities. Every person can, through application of effort, develop an incredible memory, mental mathematics skills, great expertise with musical instruments, a solid understanding of engineering, and so forth; in short, every human being is a ready-made genius. The mind is a tool which itself requires skill to use.
Old and new memory techniques, mental math strategies, and study techniques allow us to maximize the use of our mind. Textbook study profits greatly from the SQ3R study method (all modern methods are effectively SQ3R with different names); mnemonics enhance any formal and informal study; anyone who learns mental math through soroban and anzan methods will quickly become a human calculator. Ericsson's research into expertise tells us that a person learns rapidly when they analyze their difficulties and flaws as matters of inappropriate technique, focus on improving those weaknesses, and practice in a way which targets such skills while giving constant and immediate feedback--in short, knowing exactly when we're doing it wrong and why it's wrong gives us the ability to correct and rapidly improve our abilities. It only takes application of technique.
Humans are different. Our experiences shape us; sometimes, brain damage or genetic and biological imperatives shape us. Women think differently than men; asians have different cultural interests than europeans; but we all have the ability to deliberately bestow upon ourselves any skill we wish. Normal humans can even emulate strange humans: synesthesia can be simulated, and this simulation can be leveraged to improve memory; distinct personalities can be created inside the mind by force of will, and a writer or actor can shape coherent, independent characters and complex interactions from these imaginary individuals; artists train themselves to dull the left prefrontal cortex, making themselves capable of the amazing feats of brain damaged savants. Anything one human can do, another can do.