"Education is what remains after one has forgotten what one has learned in school" - Albert Einstein

You can't teach an old dog new tricks.

As Barney takes the stairs to Robin's apartment, two at a time, all he can think about is how he's tired of pretending. He's just so tired of struggling against how he feels about her.

Not that what he feels is straightforward and yeah, okay, maybe this he is being shallow wanting to backslide this badly. But maybe it's more than that. Maybe he's wanted to try again with Robin for months now. And if Robin doesn't want that too, deep down, why would she suggest hooking up again? Sure, Nora's cool. He likes Nora in the same way that he liked Robin when he first met her. He can't deny that there was an instant attraction there. But with Robin, there is all this history, all this growth. Robin already knows all his bad points, all his good points. He doesn't have to explain them to her and risk her judging him. Jesus, any woman in their right mind would judge him for the things he's done! The idea of starting from scratch – of learning all about a new person from the ground up – that just scares him. And this time he's actually tried to fight that fear. He even pieced together the shredded napkin on which Robin had written Nora's number. But it's just no good. His heart isn't really in it.

And perhaps that's the trouble? Robin had his heart first. And if Robin still wants him, how is this not a no-brainer?

Still, Barney is nervous as he walks into her apartment. He tries his best to be cocky, to keep up his usual front of awesome, but deep inside he feels a like a little kid who's about to do something he knows is wrong. "Robin, give it to me," he says, turning as she comes out of the kitchen. The words come out sounding resigned and strangely defeated, not confident at all.

And she doesn't react how he expects.

Robin closes her eyes, sighs, and then lets him have it with both barrels. She's angry with him and he's so thrown off guard that he only catches parts of her rant. He hears "Damn it, Barney!" and "Failed my test" and "I tried to root for you" and it makes him feel even more like a kid than ever. At school he was always a bit of a dork, a teacher's pet, and yet somehow he was always getting shouted at. He has this memory of Mrs French, ironically his math teacher, getting angry with him for screwing something up, for forgetting something on a test. He was always forgetting stuff. Lessons just seemed so boring compared to everything else in the big, bad, exciting world. He was so easily distracted, even when all the other kids seemed to be able to concentrate just fine.

And that left him with all this residual guilt.

He respected Mrs French in the same way he respected his Mom, that he respects Lily and Robin. When a strong woman shouts at him, it speaks to him at the most primal level.

He can't deny that it's kind of hot.

But also, there's the fact that he knows Robin. He really knows Robin. He's had years to study and become an expert on this woman. He knows there's no point in pushing her, even when she's clearly still into him, even when she looks amazing in that sheer green silk shirt which clings so invitingly…No! There's no point in pushing this. For once, he doesn't feel bad about lying to her, for backtracking. He's even a little amused.

"The number," he says. "Give me the number." And he fishes the sticky mess of paper napkin with Nora's number out of his pocket. He blames Robin for her handwriting, and they almost get into a ridiculous fight about it, but it's like they both know they're doing a bit. She even calls him an idiot, and he knows what that word means in Robin's moon-man language. It means that she's still in love with him, although she'll never admit it.

Oh yeah, he's an expert on Miss Scherbatsky, and he knows how to play the long game. Sure, Nora's fun, she even makes him smile when he thinks about her. But the cynic in him tells him that relationship is doomed before they even start.

Nora's too much of a romantic. In a way, she's almost adorably innocent.

Him and Robin – they were never that innocent. But that was more due through nurture than nature: Shitty Dads, embarrassing pasts, a problem with authority, a deep-seated need to slack off whenever the occasion arises. In so many ways, they are just so similar.

But the timing just isn't right.

When Robin tells him to "Go get her," it makes his heart swell like he's eleven years old and he's just gotten an "A". Because she believes in him.

Even knowing everything about him, even being an expert on Barney Stinson herself, Robin still believes in him.

And that's enough for him right now.