"EUREKA!"
Teo heard the usual yelp of excitement from his father's laboratory. He wheeled up the steep ramp the Mechanist had built for him, careful not to slip off like he had done multiple times before. Once on the second level, he turned a sharp left, almost toppling out of his chair in the process. He expected a new catapult, a clever candle, a telescope, anything, but what Teo got was far from it: a tall steel cup covered in sheet metal with a hole drilled into the top from which a long, thin, tube-like object protruded.
"What is that?" he asked.
"Why, it's my new invention," exclaimed the Mechanist. "It'll change the way we look at the world! It'll be the greatest breakthrough of the century! The beginning of a whole new realm of science! Isn't that exciting?"
"Right…" said an apprehensive Teo.
"Why you are looking at me like I'm weird or something?"
"I dunno dad, that's just a pipe jammed into the lid of a cup. It's just not… normal."
"What's so weird about it?"
"It's a cup. With a tube sticking out of it. I'm a teenage boy. Do the math."
"I don't follow, but listen to this: Have you ever been holding a glass of water or juice when you knocked it over and spilled everything? Are you tired of losing the cork? Fear no more! The patented, as soon as patents are invented, state-of-the-art Air Pressure Protection Apparatus, or the APPA, solves all those problems! Now you can take your drink anywhere without the worry!"
"Dad. Why in the world would I want to do that? I don't really go anywhere. I have a tough time going to the bathroom. I'm handicapped. And we're stuck on a freaking mountain IN THE MIDDLE OF NOWHERE. The "APPA" wouldn't be useful."
"Well, we could always sell it–"
"On a mountain, remember?"
"But it was a great idea! And it's the principle that counts!"
"Sorry to break it to you, dad, but face it. Nobody is going to want to drink their water by sucking on a tube. Especially guys. Girls, not so much. But seriously, don't you see what this would cause?"
"Nope."
"Dad, sometimes I doubt your sanity. Just saying."
"Aww," groaned the Mechanist.
Two months later, the Avatar came to visit the Northern Air Temple for the first time. He was initially perturbed that his people's home had changed so much, but time changed his mind. After the victory against the Fire Nation in which they lost the War Balloon, the Mechanist approached Aang and presented him with his invention from two months before.
"For your generosity and helpfulness, you can have this: the APPA," he said. Teo face palmed, muttering, "I thought he threw that thing out."
"The what?" said Aang.
"The APPA. You see, now you will never spill your drink again!" the Mechanist said excitedly.
"I OWN THE RIGHTS TO THAT NAME!" shouted Aang. "I'M TAKING THIS TO COURT!" His tattoos were beginning to glow from the Avatar State.
"What? You can't do that! Courts haven't been invented yet!" protested the Mechanist.
"OH YES THEY HAVE! JUST WATCH EPISODE 205!"
"Hey, aren't you breaking the fourth wall?"
And so Aang got so pissed that he didn't look where he was looking, which caused him to fall off the mountainside where he plummeted to his doom because he forgot about his glider. And because he was in the Avatar State, the Avatar died, Fire Lord Ozai won the war, and the world became the place it is now.
Washington, D.C., 1887 A.D.
Marvin walked just outside the city one cold winter day. Suddenly his foot struck something hard: it was a steel covered cup with a tube sticking out of it. Hey, that could work…