Have you tried google yet?
It's might be real, and he just doesn't realise how many people don't know it; that, or he knows, but wants to spread it's use. [I think it'd be a better idea just to list them in the latter though.] It's definitely not as well known as the "three R's" if it's real.
My guess is Knowledge or Know-how would be one. [getting to know the material]
It's a real stretch but if it's anything like the "three R's" [of which only one starts with an R] then things' like
intensity could possibly be one [N-ten-suh-tee].
I went through the KN section of an online dictionary w/o findin' anything, So that's my best guess.
What does yr prof. teach?
Maybe you are right, and this world isn't anything special after all.
But as familiar sights look different when seen from on high--as even when it's raining, blue skies spread out above the clouds--don't you think that the way you view the world changes depending on how it is perceived?
O, what a wonderful world! Even if it's a lie, if you believe it, maybe you'll feel happier than yesterday. Right?
Good or bad or something amazing: it isn't about what you do; it's about living without regret. That's it.