I understand what some say about being needy - if you make 3 strikes instead of 2, then you come along as needy. However, if we're assuming the girl ISN'T interested, what's the difference between 2, 3, 4 or 5 strikes?. ( over time of course... otherwise it's just plain stalking). I mean, you've already got the "no" (or it's implied). What's wrong with trying something else as long as it's not invasive?.
The OP is talking about a girl that's not an oneitis yet she is "special" enough to do an EXTRA effort. He is talking about her personality so I think it's clear he looks forward knowing her better, possibly a relationship, and not just an ONS 'cause she's hot.
I think there should be a middle spot between stalking the girl and not giving a damn. Something like a "Hey, if you don't want me, that's ok, but I'M NOT GIVING UP THAT EASILY ON YOU". I'm not an highly experienced guy but you can't tell me that a girl doesn't like to feel she's SPECIAL. And I'm not talking here about kissing her a** or buying her gifts or being all over her, just the fact of NOT GIVING UP and keep trying, without being clingy or needy, heck, maybe even not even being in contact with her for a month or two.
The key, of course, is being able to move on with your life, spin plates, and stuff. A full blown oneitis would paralyze you so you'd think this is the only good girl in the world and you would stop looking for others. In that case you need to give up for your own sake. It happened to me, I'm a survivor. But I still get the feeling that X chick is "special". I relate to the OP. My two cents: KEEP TRYING while moving forward with the rest of your life/plates, and improving yourself. Am I an expert DJ?. No, sorry to disappoint you. Is it delusional to think you can get her if she's not interested NOW?. Yes. Is it delusional to think you may EVER get a chance with her?. Who the heck knows?. Even if it's a 10% chance - it's worth it as long as you DON'T GIVE A DAMN in the meantime.
I probably deserve to be banned from this forum after such a blasphemous post...... but it's my sincere personal opinion.