Preventing amnesia so that I can remember where my keys were (and all my other stuff)

Late game, I had made it to the Wizard's Tower. Lovely lovely, doing well.

Pretty sure that I had wished for GDSM (though I have since died, so can't check), but something was bothering me. Once I killed Rodney I'd thought I was fully prepared for his harassment, but poof, he cast amnesia on me, and I forgot what everything was.

My question is, does GDSM provide MR so that amnesia fails? And if not, how can I prevent magic from affecting me late game?

Solution 1:

The Wizard of Yendor can't cast amnesia, it isn't a spell effect. The only sources in vanilla nethack are scrolls of amnesia, which can be avoided by not reading them; or mind flayers/master mind flayers, which are often avoided through genocide. The Wizard of Yendor is capable of summoning master mind flayers through the summon nasties monster spell, whether he is present or not.

If genocide is implausible, a greased helmet also defends against the amnesiac int-drain attacks, although the grease can wear off.

Mind Flayers and Master Mind Flayers are both represented by a purple h, the same symbol as a dwarf king. Be careful that you know what you are attacking.