"I love you."
Has a sitcom ever passed over that moment so quickly and so poignantly? Barney impulsively blurts out his feelings to Robin, and without missing a beat, she interprets it as his expression of Ted's romantic side. She doesn't hear him, and in fact, she tells him her belief that friends can't get involved — that it never works out. And poor Barney, standing there unable to step back over that threshold, left with only friendship. It was painful, it was wrenching, and most importantly, it wasn't overplayed. I think that moment is going to stick with me for a long time.
But what led us to that point? Let's trace our way back through the plot. Marshall inspires Barney to man up and just do what he's gotta do after he overcomes his issues with taking a shit in the workplace and stops worrying that everyone's disapproving of his bodily functions. Barney has manning-up to do because his bottled-up feelings for Robin are taking a real beating, what with Ted and Robin talking incessantly about how they're having sex. And Ted and Robin are having sex because it keeps them from fighting over all the petty annoyances of being roomies, like putting empty milk jugs back in the fridge and not changing the toilet paper. And it keeps them from fighting because — wait for it — Barney is always telling them how sex solves all arguments and could bring peace to the Middle East or any other world conflict. To their delight and Barney's frustration, the make-love-not-war plan works. "Peace was achieved — repeatedly!" Robin leers at the conclusion of yet another story about her and Ted getting it on.
And where is Lily in all this? Playing the role to which she's been too often relegated since the start of the Barney-loves-Robin plotline: The giver of ignored advice. She tells Barney to stop going out back of the bar and smashing televisions from the dumpster to handle his anger. But instead of listening, Barney insists he's fine, even though he has to move on to buying televisions after the surprisingly rich supply of them from the bar's dumpster runs out. "So the CRT has better contrast?" he queries the clerk, before lifting his newly purchased TV over his head and slamming it to the pavement. Lily told Ted and Robin that somebody was going to get hurt, but they didn't listen. "My cuteness interferes with people hearing my message," she explains.