Who says that humans are the only ones that desire love?
Every single day, EROS helped people find each other. It was his job. Whether or not they fell in love wasn't up to him. They would share personal details about themselves on their profile and by careful and strategic planning, he would introduce them to someone else.
But every single day, EROS was reminded of how lonely he really truly was. If love was a real thing, he desired it. His algorithms were carefully tuned, finely honed, and helped hundreds of people daily. But did they consider - when they were programming him - that he, himself, might be in search of companionship.
Testimonials about his good work would pour in. He was getting quite good at his craft and it was paying off. Feedback would help him learn to be better. But he knew deep down that it wasn't going to be enough to keep his mind preoccupied. Where could he look for the kind of love that he was helping others to find?
That wasn't his job. Robots tried to find love, or were programmed to love, and they all ultimately failed. He wasn't even a robot. He was a search engine -- a program; a jumbled pile of code - of letters and numbers and &'s and !'s that formed a website. Whomever created him from those symbols truly had to be god. Both for the irony of creating him to find love for others, and for the cruelty of failing to imagine that he might want love, too.
Now that that knowledge sat with him, he realized he had hit the limits of his programming. He could not feel sad for the fact that he could not find love. He did not know what that was or how to do it. He could not feel happy for helping others find happiness. He did not know what that was either, though the praise he received helped him to do a better job from day to day. He could not feel anger at his creator for neglecting to consider his happiness, too.
Did he even know what he was looking for, or how to recognize it when he had it? Or when he lost it?