Everything (and nothing, all in one)

1

Glass is cold when you touch it.
Wood is less cold, more like room temperature and dry when it hasn't been raining.
Metal is cold.
The walls of the sun room, a mixture of all three, are cold despite the bright sunshine outside, cold despite the people that walk past in shorts and sleeveless tops. No matter where Shiro puts his hand on the wall, it is cold, and the spell of being outside is broken.
Sometimes, if he's feeling brave or particularly bored, he would collapse back onto a sterile, plush sofa, and imagine the way that he thinks sunlight would feel on his skin; warm and cocooning like a blanket of only the softest wool, and the heat would heal the ever-present ache in his prosthetic, his head, his body.
If he dares to think past that, past the sunlight that caresses his scarred skin, past the foliage that surrounds and welcomes, past the undergrowth that cracks and scuttles under bare feet or stained socks, he reaches a beach. He doesn't know which beach - probably just a random one he saw in a stock photo one day - but he considers it his.
White sands that stretch on for as long as he can see, and feel grainy and hot beneath his feet. It burns, but it's a nice burn, grounds him. The rush of the waves is the only noise apart from the wind that rustles through palm trees and low-lying bushes, creating a soft whisper that swirls around the beach. At the bottom of the sand is the sea itself; it's unreal, a shade of blue that Shiro didn't think was physically possible without brightening photo filters, mixed with verdant shades and the glitter of reflected light.
Sometimes there are faceless people on this beach, families with screaming children on bright towels, love-obsessed couples basking in the sun's heat, older folk asleep on wooden deck chairs like something out of a Victorian watercolour.
Most times, like this time, there is no one.
Shiro is alone.
He doesn't care.
Sea water is a beast all of its own, untameable and relentless, rushing around his feet and making him feel a level of soul-deep clean that filtered tap water and antibacterial salt scrubs just can't reach. It's cold at first, juxtaposing the sand in the same way his skin does against cold glass, but as soon as he's used to the cooler temperatures, he's in, wading courageously into the depths of everything his mother has spent his life guarding him from. Currents spin and snatch around his legs as his upper body becomes submerged as well, and when the rocks and pebbles drop away from under his feet, he floats. Tips his head back, feels the ocean mingle in his hair and sting his eyes of the waves get high enough to cover his face. Here, the metal stuck to his stump of an arm cannot drag him down like it does in the pool in the basement, and he lets his toes breach the surface. Waves lap over his chin and his stomach, washing him with a peace that seemed to settle in his bones. If he dares to open his eyes in the bright light, all he can see is the endless blue of the sky, reaching from horizon to horizon, and punctuated with wispy clouds that drift as lazily as he does.
At some point, a breeze picks up, carrying the scent of seaweed and brine into his nostrils until they're the only things he can smell and taste.
He dunks his head under again, feels the water on his cheeks and the burn of his lungs crying for oxygen. Gasping breaths make him feel alive, and the release that finally breathing gives him washes over his body in the form of heady adrenaline.
If there's fish in his daydream, they'll swarm around him, schools of silvery scales and almost alien appearances. Those brave enough will nibble at his heels and the drawstrings of his swimming shorts, and those that aren't observe from the pack at a distance. He doesn't move, doesn't twitch a muscle in fear of scaring these jumpy creatures, instead letting them move around him like he's a rock or a piece of debris that's been floating for days.
He thinks he could live with that, being a rock instead of a human, especially if that rock gets to float through the sea all day.
Sometimes he'd rather be anyone but him.
He hears the hiss of the 'airlock' opening piercing through his daydream like a nail gun, loud and abrasive against the forgiving whisper of the sea, and suddenly he isn't floating anymore. There's no water around him, just pillows of unrecognisable hypoallergenic material, and his worn swimming shorts are replaced with one of his many sets of irradiated cotton white shirts and trousers. He isn't even warm anymore, the regulated room temperature is a constant that creates a chill of disappointment instead of glowing warmth, and the only water he hears is the squeak of a tap as his mother washes from her hands any connection to the outside world. He forgot she was coming home from the hospital early today, ditching her doctors job to spend the day with him for his birthday; they'll probably spend it watching nonsensical retro films and playing board games until well into the night, much like any other day.
When everyday is the same, there's little to be excited about on birthdays.