the thing about the 'forget' scene scene from RFM which makes it work, is the exchange between Spock and McCoy beforehand, with McCoy explaining why he feels sorry for Spock, not Kirk. The little speech with Bones explaining WHY humans treasure love so much. I wish I could remember the whole thing exactly (time to stream it off of Amazon tonight!), but Bones talking about the 'glorious triumphs...and the glorious failures also....these things you will never know, Mr. Spock...all because the word 'love' is not in your dictionary.", and then, almost to himself, "I still wish he could forget her....good night Mr. Spock." Its played, as always, perfectly by Kelley, and then, when McCoy leaves, Spock kind of puts his hand up towards the door, as if he is locking mentally, THEN turning to Kirk.....all very well written...very underplayed by all. And extremely moving.
Considering the episode itself is kinda eh, and that the show was limping towards its conclusion, a pretty amazing piece of film.