Try 15 years. There was this cute girl who’d always kind of hang around in the background, but never said a word. She made a big mistake by repeatedly sending her solid-10 friend to talk to me about her, and we fell in love instead.
Years later, another girl tried the genius tactic of inviting me and about a dozen gorgeous female friends of hers to a bar, then sitting straight across the table from me and just glaring at me intensely. I started thinking “gee, she must really hate me” and made my move on the girl sitting next to me. Who was the only one I could actually talk to, because it was just too noisy in that bar.
There were other times when I immediately picked up hints from girls because they made it abundantly clear what they want from me, but they simply weren’t my type, so I basically ignored them, which only made them try harder. I realize now that to them, genuine disinterest and blissful ignorance must be indistinguishable.