For the last mothersmurfing time I understand the entire scene. Doesn't stop ME from THINKING that it's utterly goddamn pointless. You know when Cloud goes through a third of the game having no idea why he handed Sephiroth the Black Materia, or why he attempted to kill Aeris? Terra spending more than half her game feeling demonised? Cecil's misgivings about being a Dark Knight? Whereas Zidane goes doo-lally for about five minutes? The fact that the scene is incredibly short and is then completely discarded and ignored throughout the rest of the game is my biggest beef of all.
Um, Cloud handed Seph the Black Materia and the next time we see him is his little thing with Tifa where he remembers everything...
Plus he never wondered why he tried to kill Aeris. In fact, that whole thing was forgotten in the wake of Seph actually killing her.

And no, it's not discarded. There was nothing more to be said about it...it be like right before the final battle with Jecht, Tidus goes "hey Yuna, remember that time in the spring?" Or before the party fights Ultimecia, Squall goes "hey Rinoa, remember that time I carried you to Esthar?"
The player remembers these and they don't need to be said later on.

Other than showing that Garland seriously sucks at breaking people, what was the point of that scene?
Kinda bovious...the theme song of the title screen is called "A Place I'll Return to Someday" and we get the little story Zidane tells Garnet about the home he went searching for.
He's finally presented with the home he had longed for and he learns his only reason to live is to kill everyone he knos and loves.
That scene is him putting his former dream of a home behind him and settling on he has a home already with all his friends who will stick with him no matter what he is or how he is.

I revoke my previous two cents, and say Garland from FFIX. Kuja and Brahne took the spotlight for two and a half discs (give or take, Brahne died at the end of disc 2) and then Garland appeared for five minutes, failed to break Zidane and then died when your little group of pwnies ran into him.
He also was the one who nearly killed Kuja and the party, destroyed Alexander and Alexandira's Castle and well, was intimidating because he was the guy Kuja ranted about for a good bit of Disc 3. Then we find out what he is and what he's doing.
His role in the game as about as vital as Yunalesca's in FFX.