This was a very nice little vingette, and could be either a cool allegorical story or the first part of something bigger. You have some great imagery here, and painted an excellent picture of what was going on. I think you could use some more sensory details to show me what the grass felt like under this guy's toes (it must be an odd sensation, to someone who has never stepped on natural grass before) or the wind across his face, and what the smell of the natural world was like. Also, perhaps some more metaphors and similes could get across the feeling too, perhaps adding one to the last line to really get across just what kind of sadness he feels. You do a very good job of creating a conversational narration, and you have some excellently chosen words.

Keep writing and I'll be sure to keep reading.