Keith has always been a loner.

As a kid, he despised the hustle and bustle of school and noisy classrooms. Busy foster homes had driven him up the wall, and for those homes, he tried particularly hard to be a nuisance so that they would send him back.
Which had always worked, by the way. Keith took some measure of pride in his own stubbornness, after all.

Even getting kicked out of the Garrison was a tad relieving (though still hard to swallow); if there was one good thing to come from getting the boot, it was not having to deal with all the people . The constant attention that he had never asked for to begin with, both from teachers and classmates alike. The constant feeling of being surrounded. Being placed up on top of a towering, lonely pillar.

Either way, he's always preferred his own company, listening to nothing but silence and his own quiet breaths, watching the starry night sky.

So he's not quite sure how he became so accustomed to the company and noise of the others.
The buzz of casual chatter between them transforms from mildly irritating into something... nice. White noise, if you will. It's calming.
Someone starting a conversation with him is no longer a rare, dangerous affront that he has to parry away; it's become something of a norm these days, and he finds that his guard is no longer as solid as it used to be. He allows himself to make conversations last longer than five seconds, making them into something... more. Responding with full sentences instead of monosyllabic words and quiet noises of either agreement or annoyance.
It's still hard for him to start up conversations that don't relate to any life-threatening tasks at hand. But he's been working on it, working harder than the others may even know.

Shiro has always been a comforting presence in his life, but now he feels even more so; they're working closer than they ever had before, reunited and joined against a common enemy.
Pidge is nice to be around. She'll go for hours without talking, tapping away at her computer's keyboard whilst occasionally mumbling to herself. Keith kind of enjoys sitting nearby as she does so; it's quiet, yet not lonely.
Hunk is... hard for Keith to adjust to. He doesn't think he's ever met someone who's just so genuinely friendly . But the idle chatter Hunk provides- and the oddly wise, soothing aura he gives off- makes him actually pretty relaxing to be around.
Even Lance, with his oh-so-aggravating tendencies, has become less of an annoyance so much as... well. Keith's not entirely sure what to call it. The teasing and banter has become familiar and warm, in a way- he doesn't dread it anymore.

Sometimes he even catches himself looking forward to it.

Coran and Allura, even, are growing on him. They're certainly kinder than most of the people in his life were while he was growing up.

He can't help it. He's warming up to all of them.

Keith is almost afraid of how attached he's becoming to the others; attachments, according to his prior life experience, would only lead to pain and heartbreak later on. But with every spiritual connection required to form Voltron, with every conversation, with every single moment spent with his team...
Despite his caution, they all grow closer. So close and tightly-knit that it's like nothing Keith has ever experienced before.

Sometimes the others speak of home, and of family. Of how close families are- how, even when they argue, or if they're millions of light years away, they're still connected.
How home is warm- someplace you find yourself drawn to. Somewhere to return to after a long, hard day.

Somewhere you belong.

And sometimes, when they speak of such things, Keith pauses.
Sure, he'd never had either of those things growing up. He'd never grown attached to any of his foster families, and the closest thing he's ever had to a home was that shack out in the desert.
But now?
He's learning to understand home.
He's learning to understand family.

He has them both right here.