You see a girl you like the looks of.
She rejects you.
Why did she reject you?
There's always a reason for it.
If you understood that reason, you could correct for it, and avoid future rejections from future girls who look like her.
Most guys will pick any old reason out of the sky ("I'm too ____" or "I'm not _____ enough!"). Or they may ask women why they rejected them, which only gets them the most superficial reasons, not the root reasons.
Yet there is a way to discern her TRUE reason for rejecting you... roughly-speaking, anyhow... that way you can zoom in on correcting it with the next women you talk to.