Nobody said that two knights can't checkmate a lone king. What they said is that you can not FORCE such a checkmate. The lone king needs to help by making a stupid move like in your example Ka8 instead of Kc8.
Proof that two knights and king can checkmate a lone king

Try wrapping your brilliant mind around the difference between forced mate and helpmate.

Before you call people outrageously retarded, stop and think: "Am I making a complete fool of myself?" Because you are
That's the joke.

Before you call people outrageously retarded, stop and think: "Am I making a complete fool of myself?" Because you are
That's the joke.
You have some serious potential to be one of the top trollers on this site if you wanted to.

Before you call people outrageously retarded, stop and think: "Am I making a complete fool of myself?" Because you are
That's the joke.
You have some serious potential to be one of the top trollers on this site if you wanted to.
Troll, not troller.
I'm gonna take those two knights..... and shove them down your throat. Guess where the kings are gonna go.......

I haven't read much about chess, but recall the fact that the player with less material would have to co-operate to be mated was covered in the first few chapters of Silman's endgame book. Not even a good trolling attempt.
Now show an example where the mate is not in the corner. It can be done.
It's one of the most embarrassing things in chess that 2N + K cannot checkmate a loner. What sick demented God invented this endgame?

Why do people say that two knights can't checkmate a lone king? I heard that and thought it was kind of odd and sure enough, it simply isn't true. Here is an example of two knights and king checkmating a long king...
There must be some outrageously retarded chess players out there who can't grasp simple concepts! How easy it is to overlook key info and not get something...
I think you missed - or those you've heard from missed - the point that you can't force a checkmate: you need an "outrageously retarded chess player" to help by moving his king to a point where it can be checkmated.
Further, please don't call people names even when they think they know things without checking: after all, you didn't seem to realize the importance of the word "force" here and notice that the responses had enough class not to call you names. Please learn from their example.
Why do people say that two knights can't checkmate a lone king? I heard that and thought it was kind of odd and sure enough, it simply isn't true. Here is an example of two knights and king checkmating a long king...
There must be some outrageously retarded chess players out there who can't grasp simple concepts! How easy it is to overlook key info and not get something...