What do you want?
When do you want her?
BEFORE I DIE!!!
You know it. I know it. All your friends know it, because it's all you ever flippin talk about. "Check out that chick!" "I wanna get with that chick!" "Dude, is that a chick or just a really pretty guy?" Granted, hairy, manly, barrel-chested men are supposed to desire females; YOU just happen to do it more than everyone you know. That makes you a freak of nature. So sorry.
But honestly, this wouldn't be a problem if not for the fact that this constant desire makes you STUPID. That's why you need this rule.
RULE 9: CUT YOUR LOSSES.
They say that hope springs eternal. No matter how much doom looms overhead, there will always be the faintest spark egging us on, keeping us going. It is this spark that has kept humanity from just completely giving up and going extinct for eons.
However, if you ask a girl out and she turns you down, that hope needs to die. You need to stab it in the back, twist the knife, and watch it slowly bleed out as a smile creeps across your face, because if you let it live, it will make you KEEP COMING BACK TO HER FOREVER. You'll never give up. You'll always think you may still have a chance if you try a little harder or change your personality, but that's wrong. She'll never like you. You need to get over her, and the only way to do that is to get her out of your life. And honestly, why would you want to keep hanging out with someone that constantly reminds you of your failures?
If straight-up cutting her out of your life isn't really an option (i.e.: she's a part of your friend group), then you need to employ my patented 5 STAGES OF REJECTION!!! It's just like the 5 Stages of Grief, but backwards.
ACCEPTANCE - "That's cool. I can't change people's feelings."
DEPRESSION - "Seriously, though, why doesn't she like me? What's wrong with me?"
BARGAINING - "Maybe I can change her mind if I changed x and y."
ANGER - "She's stupid for not liking me!"
DENIAL - "Whatever, I never liked her anyway. She was always just a friend."
With practice, eventually, you'll be able to go through this process within a few short hours or less! I find it helps to find a flaw in her personality (and trust me, she DOES have one) and focus on it until it's all you can think about when you see her.
"But what if she's just got a boyfriend? Couldn't I try to wait it out or steal her away?" Well, no. Listen to this guy.