Human emotions are still a mystery to Castiel, even after being a human for a number of years.
He had never felt until he had met Dean. He had never felt friendship. He had never felt affection. He had never felt angry or betrayal or depression. He had never felt lust or arousal or desire. He had never felt true love. He had felt love before, for his Father, but not the kind of love that could break your heart or fill it up with joy. That could fluctuate between adoration and hatred in a matter of seconds. When he was an angel, he often wondered why humans fell in love when there was a chance that they could get their heart broken. Why would anybody want to be happy when they could be sad later?
He understands now. He understands because of Dean. He knows why humans fall in love. Love is the best feeling he has ever experienced. It easily bypasses desire because the feeling of desire is limited whereas love can be forever. He often pondered what love was. He tried looking on the Internet for the answer to what love was but all he got from his research was that love meant different things to different people. He didn't know what love meant to him yet but he just knew that the feeling he felt for Dean was love.
That was why Castiel liked to write. Writing helped him express his feelings. To him, it's easier to write down how he feels. He didn't understand emotions when he was an angel. He had never felt them, so he never learned how to express them. He had watched Dean and Bobby to try and glean and understand on how he should show his feelings but they showed their emotions in very different ways. It was confusing. Dean showed his emotions though his body language, not his words. For example, whenever Dean crossed his arms, Castiel knew he was being defensive. Bobby hid his feelings behind a gruff tone and exasperated but affectionate insults. To many people, the word "Idjit" means idiot but to Bobby Singer, and anybody who knows him, the word "Idjit" means that you are cared about by him.
Castiel would write about his day. He would write about his opinions on many things, including political events that he did not understand. He would write about movies and television shows that he had recently watched. He would write down memories of his time in Heaven, which often left him with a headache, as it took a lot of concentration to remember them. He would write about how annoying and cantankerous their next door neighbour, Mrs Dubose, was. He would write about absolutely anything.
The thing that Castiel loves to write about the most is Dean. He writes about how Dean's freckles show more in the summer than any other season because of the Sun. About how peaceful he looks when he's asleep. How, when Dean truly laughs, it reverberates through his body, making his body shake with laughter and his cheeks flush with exertion. He writes about Dean's body. How his shoulders and most of his back are covered with freckles. About his bowlegs and how they never touch, even if you push them together.
He could write about Dean all day. Dean was the most interesting person to write about, even if he didn't think so himself. "I don't see how you haven't ran out of things to write about me. I'm not fascinating, Cas. I never have been and I never will be". Whenever Dean tells him this, he writes down the many reasons he loves Dean on post it notes and leaves them around the house. Dean keeps every single one - in a box in his bedside drawer, although he would never admit that to Cas because of the chick flick moment that would follow.
Castiel may not know what love means, but he does know what being in love is like. It is amazing.
