Flash Fiction Piece

Here is my first ever piece of flash fiction....i really think YWS should has a flash fiction section....anyway tell me what u think.

“I wish that I could go back in time,” the girl said dreamily, “I could change the past.”
“That’s impossible” the boy said, “Assuming you even found a way to go back in time, you would almost immediately cease to have ever existed.”
“You spend too much time dreaming anyway, if you would just think rationally for once you would realize that things like time travel couldn’t exist in reality”
“It seems,” the girl started, “It seems that the problem with this world is that reality just obscures true existence”
“But without reality there wouldn’t be existence” the boy said.
“Do we exist?” the girl asked with an inexplicably mischievous look in her eye.
“Of course,” said the boy “Don’t be absurd”
Just then, Lucy woke with quite a start and stared into the oblivion that was the darkness of the night. It must have been a nightmare she thought, but couldn’t for the life of her remember its contents.

Erm, I'm confused.

This is very short, even by flash fiction standards. This is only 165 words, and most flash fiction ranges from 250-1,000 words. There's really nothing but dialogue here, and a short bit of what might be considered setting at the end.

Elaborate! I mean, the dialogue is something worth pondering, but it's kind of on its own with nothing to back it up. No reason to care. No reason to keep going other than the fact that you don't have far to go.

I'd like to see this considerably longer.

-St. Razorblade

P.S.: Unrelated to your piece, but please spell out "you."

I was confused. Was she in the future of something? There was a lot of dialouge, I used to make that mistake a lot. It would be good if you could write more, add some more detail about the setting, their feelings and what's actually going on.

could be a dystopian setting, I suppose.

But not at all in my tastes..