Disclaimer: I do not own Sherlock, nor do I own the song.
I'm not afraid of being alone, but being alone is better with you. Life is better with you.
-Michael Franti and Spearhead, "Life is Better With You"
Sherlock likes being alone. In fact, he craves it. He needs it. He never lets himself get close to anyone, either platonically or romantically. If he can feel himself warming to someone, wanting-even a little bit-to be close with them, he immediately pulls back, pushes them away before he can get caught up in attachment, closeness, even-God forbid-love.
He makes excuses for it. Love is dangerous, he tells himself (and anyone who'll listen). It makes people stupid. It would interfere with his work, and nothing is worth that. He tells himself these things over and over again, hoping that he'll eventually come to believe them. The truth, however, is that he's scared. Emotional closeness terrifies him. It isn't something he can immediately understand, like-well, like everything else. If someone tries to connect with him, no matter who they are, he panics and pulls away. That's how it's been with everyone-with Molly Hooper, with Greg Lestrade, even with Mycroft, his own brother. And that's how it should have been with John Watson. John should be a flatmate to Sherlock, nothing else. There really isn't any reason why Sherlock's relationship with John should be any different than his relationship with anyone else.
And yet it is different. John, quite unexpectedly, has somehow worked his way into Sherlock's life in more ways than one. He isn't just a flatmate to Sherlock, or even a colleague. He's a friend. And, Sherlock, miraculously, doesn't mind. He isn't pulling away from John, isn't scared of getting too attached. He's going along with it, and he feels safe-something he hasn't felt in a very long time. And he's happy, truly happy. Not the exhilarating sort of happiness he feels when he's on a case, but something different. Softer. It's new, it's foreign-and it would be altogether terrifying for Sherlock if he didn't, for whatever reason, feel so safe with John.
As time passes, Sherlock begins to realize something. The realization comes slowly at first, then faster, until it's right there, crowding his mind, not leaving room for anything else. All of his thoughts, all of his actions, are consumed by the realization that he is in love with John. He doesn't know how it happened, but he knows for sure that, yes, he is in love. And it's frightening-yes, terribly frightening. For the first time since he met John, Sherlock feels a hint of the panic he feels when interacting with anyone else. It's tempting to pull back, to bring this friendship or partnership or whatever-it-is to a sudden end. But what he feels for John is strong enough to make him stay and not retreat like he always does. And, anyway, it's rather thrilling, being in love.
Being in love. How strange to think that these words now apply to him. Sherlock didn't even know he could fall in love, but as he knows all too well, even the most well-educated of guesses can still be proven wrong at any moment. He's in love, and he's in love with John, and it's wonderful.
And it becomes far more wonderful when Sherlock finds out, through a series of rather amusing mishaps, that John feels the same way, and even more so when a kiss, one simple kiss, confirms what they both already knew: They're stuck with each other. They're together, always, for better or for worse.
Sherlock still maintains that love is a dangerous disadvantage, that it's an extreme risk. But now, it's a risk he's willing to take. Maybe it's safer to be alone, but Sherlock is infinitely grateful that he no longer has to be.