On the first day she learns about the Shanshu, that her long-lost lover has been working toward her and humanity all this time. When he appears at her door with a bouquet of flowers and a sheepish smile, she can scarcely believe it.
Well, she doesn't believe it, at first. Too many years of being unlucky in love have taught her never to take windfalls like this one for granted. So she won't even kiss him at first, afraid to acknowledge something that might slip away at any second.
Willow and Giles run him through countless tests as he watches her imploringly, but she can't come any closer, not until she's sure. But once Giles reassures her that it's permanent, his soul is permanent, and he's a happy and healthy human being (albeit with some vampiric superpowers), she runs into his arms and plans to never leave them.
On the second day, he learns that she's never really recovered from Angelus's cruel words years before. She won't look him in the eye in the morning, and while she seemed to exude a primal sexuality the night before, now she's bashful and virginal all over again. Only once he tells her he loves her and all she's done with him does she relax back into his embrace, preparing for round two. They spend nearly the entire day in bed, which suits him just fine.
He also learns that Buffy isn't quite as talkative as she used to be, and there are long silences, too many of them for them to be comfortable. He tries kissing them away and she gives him a sad, understanding smile that says she knows exactly what he's doing. But that's okay, and by the end of the day, they're finally sharing in low, cautious tones.
On the third day, she learns that he really likes saving people. Back in Sunnydale, she remembers that he'd only help for her sake, but now he's become so much more than that, a trained warrior for the Powers That Be. He rarely steps on her toes on patrol, but she can see the joy in his eyes when an innocent victim goes free and she begins to love him a little more for it.
He's slowly emerging from the protective shell he's always kept around him, that air of being too old and closed off from her that had bothered her so much back in Sunnydale. Now she's meeting LA Angel, who speaks of his friends and his work there with glowing pride, who's prone to whining when she takes on a demon he'd called for himself, and who wears too many emotions to measure on his sleeve. And she thinks she's beginning to understand him.
On the fourth day, he learns that she doesn't want to discuss Spike, which rankles him more than he admits. She's cagy and curt when his name comes up, and he's beginning to suspect that she loved the other vampire far more than Spike claimed. He broods through most of the day until she sits with him and whispers that it doesn't matter, that Spike's gone now and she loves him and only him.
He asks her what she'd say if they had both arrived and she laughs wryly and pats his hand, murmuring, "Don't push it, baby."Baby. He likes that, and so he lifts her and carries her to bed, and they never discuss Spike again.
On the fifth day, she learns that he has a son. She struggles to control her desolation at hearing of his affair with Darla, but he sees it anyway and thanks her silently with a kiss. He explains the whole story and she weeps for him and his losses, for the way that happiness has eluded him for so long.
She also learns that he loved Cordelia, and she's surprised at how easily she accepts that news. But she's long ago realized that love doesn't have to be constrained to one person, and what matters is what they have now. She loves Angel with all her heart and being, and what came before is inconsequential. So she whispers condolences for his loss and lets him pour out his miseries all over again.
On the sixth day, he learns that she's no longer a child. He'd known it intellectually before, but now he understands, sees it in her selflessness. When once she'd come to him with her teenage issues and dilemmas, now she encourages him to speak about himself, no matter how much some of the details hurt her. She puts others first, saves her emotions in favor of understanding his, and he can't help but worship her just a bit for it.
On the seventh day, she learns that they're incompatible. She's long ago outgrown the old need to be taken care of, and now she needs to be the one in charge. They begin to argue and fight wordlessly for dominance in the relationship, and she worries for their future.
On the eighth day, he learns that she can't bend without breaking, and when she finally surrenders to the push-and-pull they've had going on, she's suddenly weary and lost, a child dependent on him again. He loves her too much to let that continue, and he struggles to learn to surrender himself to her. She begins to regain the lost confidence of leadership and he remains by her side, for the first time in his life a follower instead of a leader. It's hard to adjust to, but she's worth it.
On the ninth day, she learns that there are some things they can't get past, and one is lies. He has Shanshued once years ago, before he even knew what it meant, and rejected it completely, instead reversing the day they'd had together. He's gone into her mind and taken out memories that would have kept her yearning only for him for years, and she feels violated, hurt and disgusted that he would keep them from her.
She also learns that when she tells him to leave, he's all too quick to go.
On the tenth day, he learns what life is like without her. He's never wanted to know.
On the eleventh day, she learns how loneliness feels at its worst. It's never hurt this much until she finally risked all her happiness on love, but remembering the first eight days is enough to persuade her that it was worth it, despite the gaping hole torn from her heart when it ended.
On the twelfth day, he learns that her friends have finally accepted him, have seen how happy they were together. They're just as desperate as he is to reunite the couple, but he shakes off their prodding. She'll come back to him if she wants him, and he can't force that on her.
On the thirteenth day, she learns that Willow and Xander have been playing matchmaker with no results. She sinks back into despair that even hours of mindless slaying can't cure.
On the fourteenth day, he learns that she's gotten so used to him leaving that it has never occurred to her to follow him. It's his responsibility now to show her that he's not going anywhere, and he's going to win her back with all that he has. He puts his heart on the line and geta ready to grovel.
He also learns that she's more likely to throw out flowers when she's angry than chocolates, and she'll eat the latter even as she pours out her anger and frustration to him. He waits for her to finish before he speaks, and she grudgingly agrees that the past can't be changed. Then he gives her a vial Willow made for him, and as she remembers, she wraps her arms around him and doesn't let go. He doesn't need to learn that he's perfectly fine with that.
On the fifteenth day, she learns that he's still hopelessly old-fashioned sometimes, and he proposes to her that night on patrol. It's so casual that they're both a little startled by it, but he assures her that he meant it whole-heartedly. She says that it's too soon, but when he points out that they've been waiting eight years, she concedes and accepts. It was only a matter of time, anyway.
They both learn soon enough that they're going to keep learning as little tidbits escape each day. One day, it's that he likes chunky peanut butter; the next it's that she's secretly yearning to finish college. They can't afford to hide anything, not when they have five years to catch up on, five long years that have changed them irrevocably and turned them into strangers. It can be painful and confusing to reconcile that sometimes, hurtful and angry and cold. But they don't let let that stop them. Too much of their last chance at happiness is at stake for time to get in the way.
And none of that matters at the end of the day, because if there's one thing they've learned, it's that they're Buffy and Angel, and their love is worth all the pain in the world.