Why wasn't i good enough ..?

i liked this kid freshmen year and he liked two girls and one of them being me but he chose the other girl b/c he knew her better but i slowly got over him and sophomore year he dated my best friend and i was fine and after a year they broke up and i'm fine..now we're juniors and every time i look at him, it still bothers me as to why i was never good enough for him. he apologized several times for this and we've become best friends and strangers and ive met several other guys but THIS GUY is still on my mind. I feel like crying! if i'm not good enough for him then i'm obviously not good enough for any guy. i guess im completely not over him.. and idt he will ever like a girl like me. who would..