Why do I keep having dreams about this guy I like?

I work at this center where I take care of people with mental disabilities. There is a guy there that is more than 10 years older than me. We have become friends over time. Now it feel like it has potential of being more than friends. We lean on each other a lot when we are going through tough times. And that seems to making us become closer. I am really starting to think he likes me. And I feel that he knows I like him right back. I know that this can not happen seeing that I work there. And he is a client there also.