Re: Beginners with delusions of grandeur...
The entire point of my post is that you have to talk to your partner. Not instruct them, necessarily, but talk to them about when they are trying to accomplish.
Our practice is all about what if... we set up an attack and a technique and practice it. It's EASY to get out of a technique when you know what is coming. You don't give as sincere an attack, you kill your center, you sandbag, whatever. It's so easy to do, that for beginners, they often don't even realize that they are doing it.
For the partner who has other experience and is bringing it into the dojo when new techniques are being taught, it seems to me that they are not open to learning. They have watched, decided that they understood, and have already tried to integrate new knowledge into their body.
So talking to them is more likely to illustrate this point and allow them to open up to trying something different. If it doesn't, then either don't train with them... or as I said before, just focus on your training (and on protecting your partner) and ignore them.
I've trained with (and instructed) PLENTY of such individuals over the years and the primary conclusion I have always walked away with is that it is not simply my responsibility to teach (it IS, of course) but it equally is THEIR responsibility to learn (and study). If they are not ready to learn, I am not going to waste too much time trying to teach them.