What a lovely little story. I must admit that some of the scenes in the middle, with apparently different characters (the doctor and nurse, and Rex and Czar) seemed a little out of place, but Devon's struggles as to where his life is leading, and Fabian eventually really appearing to listen to him, were totally realistic. And Sam's appearance at the end served to let Devon know that his work can eventually make a difference.
If I had one even slightly negative comment it would only be that I could not understand why you gave this story a light-hearted tag.
Thanks for sharing this with us all, @Puppilull!