Not at "one that got away story really " but... Middle school or early high school (I don't understand well your USA system), one girl asked me to be her bf (maybe as a joke idk), i did 180 and said bye, just wasn't into those things yet, only cared about watching Digimon and stuff. Typical nerd with thick glasses.
I always considered her physically unattractive but she was a sweet heart with everyone, soft spoken, her mom was a religion teacher at our school.
Anyways, next year, hormones were doing its job I guess, she looked the same ugly duckling for me, but she also... I dunno, like something was calling me towards her and I though many years later, even to this day "man, I should've said yes, even if it was a prank or a short thing".
She became the girlfriend of the only "jock" (for you Americans) of the class about 3 months after my "rejection".