I gotta be real, I'm pretty sick of the "they actually knew each other as kids" trope. It's soooo overused. Some series bother to alter the formula, but most of the time it's just eh. If that friendship/event was so damn important and pivotal that you based your entire personality around it, how in the hell did you forget about it? I mean like, scientifically. Those synapses should have become really strong as you continuously think about the thing related to that memory, in this case sweets. Right? Maybe you forget some details. What words were used, the weather, what you were wearing. All of it though? That's some repression type shit, and generally people repress bad memories, not good ones.