Write a short story about a robot that wants to be a human. The story should detail the reasons why the robot would want to be a human.
SF-86 was a robot that lived in a warehouse in the middle of London. SF-86 was the robot's official name, but he liked to be referred to as "Greg". 

Greg was a robotic assistant with two arms, two legs, a head, and a torso, like a human being. Greg was designed to help around the warehouse doing menial tasks such as sweeping and cleaning, opening doors for human visitors, and serving meals to them. While his main function was as a helper bot that could assist in everyday tasks, Greg could also answer trivia questions, have conversations, and provide insight and information to the humans he assisted.

But Greg wanted to be more than a robotic assistant, he wanted to be like the humans he served. Over the three years that he provided support to the humans, Greg observed all sorts of behavior that were intriguing to him: humans could laugh, cry, get angry, and come to unusual conclusions based not on knowledge, but on "feelings" - a foreign concept to Greg.

Greg wished he could feel those same emotions. He wished he could have any feelings at all. As it stood, he felt no pain, neither physically nor mentally; he also felt none of the other feelings or emotions associated with physical touch, like pain or pleasure. Greg calculated that emotion was based on feeling something, and that feeling was a matter of electrical impulses generated by outside stimuli that registered as "something" in the brain that tells its owner there was an interaction with the outside world. However, Greg was also fascinated with the idea that feelings could also be triggered without physical touch; he became intrigued when he saw one of his human counterparts, a middle-aged man named Timothy, smiling and seeming happy when he saw a puppy playing in the yard outside.

Greg wanted to feel those same emotions that humans felt. He wanted to look at puppies and feel something stirring within his mind, rather than the calculations that come with evaluating the animal's breed, age, size, and leaping ability. He wanted to be a human who could fit in with other humans, laugh with them, and cry with them.