Assuming he's refering to the end of the game, here's a newb's perspective:

After you defeat True Ultimecia, she kills all of your remaining characters, meaning that your whole party is 'absorbed into time'. Taking Laguna's somewhat cheesy advice (use love friendship and courage to find your way),the party manages to find its way back into the 'regular' time stream. Of the six, the only two whose journey is covered are Squall's and Rinoa's. Squall does not remember his promise to Rinoa about where they will meet (at Edea's orphanage), but Rinoa does. Unfortuneately, he is not there. Now comes the confusing part: a white angel feather (Rinoa's symbol) appears before Squall. When he grasps it, he is transported to the flower field [kind of looks like the field in Selphie's limit break, doesn't it?]. However, he is tormented by memories of the day when they met, and all that came after. He is sent back to the vast 'plain of despair' and collapses. Rinoa finds him, and by the power of love, friendship, and courage (especially the first, I think), they are brought back to the real world's orphanage. Everything else is self-explanatory.

Personally, I believe that the memory of the day he and Rinoa met causes Squall so much pain because it symbolizes that he was heartless, only following orders (and he still is somewhat angsty). Note that all the memories we see are either of violence (Squall being chased by X-ATMS3 or whatever in Dollet, Selphie attacking Lunatic Pandora in the Ragnorak, etc) or Rinoa. The scenes of Rinoa are blurred, and her face blinks back between herself, Seifer (her former lover, and Squall's rival) and Ultimecia (her possesor, and possibly her evil side). Both show the negative aspects of her. These negative memories come upon him because even at that point in the game, he still is somewhat of a pessimist, not fully trusting in his feelings of Rinoa. It is only her love for him that saves him.

I think other strange events (how does the feather appear in front of Squall? How is Rinoa transported to Edea's orphanage? etc?) can be attributed to either the strange nature of the anti-time place, or . . . you guessed it, the power of love, friendship and courage!