She seemed so desperate
Uma Thurman seemed so desperate for that guy in the movie, i mean he was really cute but she definately had some issues especially at the end when she kept bothering him at that bar/club.
shareI think it had more to do with her dreams of having a better and more meaningful life than it was about some cute guy. She saw a chance to have a relationship with someone who wasn't like all of those other guys she had slept with in the past. Granted she went about pursuing him all wrong, but she was at an age when she wanted to stop acting like some stupid kid in a bar and actually have a relationship.
In that last scene in the bar when she is chasing him, she basically wanted to know why she wasn't good enough for what she wanted, why she didn't deserve more. My heart really went out to this character and anyone who has ever had a dream crushed and anyone who has ever fallen into desperation because of it knows exactly what she was feeling. It was hard to watch but Uma did an amazing job.
Don't forget that her father walked out on their family when she was young. Thus, she has had no father figure in her life.
It makes complete sense that she'd reach a point where she'd become desperate to have a relationship with a man.