Enthusiastic is when you are the one giving off or showing enjoyment, interest, or approval. Enthused is when you recieve something that makes you enthusiastic. Example: if you are watching a movie that you enjoy, then you are enthused by the movie, which makes you enthusiastic. Whenever you enjoy something, you are enthused by it, and whenever you are enthused by something, you act enthusiastic. It's alittle complicated, but I hope this helps.