My initial reaction to your story is that you sparked her interest at first but as the day wore on she got bored or unattractive. To me 2 hours is a long time. You might have just given her to much. She learned enough about you to not want to know more. I would've grabbed the smoothie , chatted for a few more minutes, got some contact info then said "well I gotta go, I see you around?"
That way at the end of the day you're that mysterious guy she got a smoothie with that she doesn't know much about, not John Doe from the gym.
That way at the end of the day you're that mysterious guy she got a smoothie with that she doesn't know much about, not John Doe from the gym.