Thanks guys.
Ok, the way JR layed it out connects the most dots for me.

You get dealt KK every 221 Hands, so this should happen about every 5639.92 Hands, to you.
When I first switched to ring, I kept getting KK running into AA - after several times I went back after the 3rd one to look in PT3. In my first 7 times getting KK, I had lost to AA 3 of them! I forget now, but I'd say all that was in the first 3 or 4k hands. Sick huh? It made me want to puke and run back to SNGs.
So based on your answers, it certainly isn't as rare as you would think without crunching numbers (at least what I would expect).

I didn't include it in the original post, but part of what also made me want to ask the question was that on the same night, I chopped with KK vs. KK and watched an AA vs. AA - and one of the guys in the hand chatted that he'd already had the same that night once before! Just makes you think, that's all.
Thanks everyone for your maths/thoughts.