I haven't played FFXIII-2, by the way, so I'm just going off of the original.
I was in the wrong place at the wrong time. That's all there was to it. If Mom and I had picked a different place to go on vacation, things would've stayed the same for us. But we went there, and everything fell apart. They found that Fal'Cie, and sent us all away. Mom ended up dead, and I was changed forever.
I thought it was over. I knew what I'd become, and what it meant for me. Everything I knew was gone, and all I had was a bunch of strangers. I couldn't have imagined a worse situation.
I needed order in the chaos of this new life. So I found myself a villain. I blamed Snow, and I set my sights on making him pay. Never mind that Mom had fought alongside him willingly. Never mind that he'd tried to help her. In my mind, it made sense.
Eventually, that plan fell apart. Eventually, the strangers became friends. And as everything I thought I knew collapsed around me, they were the only constant. I knew that whatever happened, they'd be there to watch out for me. They knew I'd do the same. It's not the kind of connection that you find every day. I certainly wouldn't have found it if I'd gone on living the way I always had.
At first I thought I was cursed. It wasn't entirely inaccurate. After all, it wasn't like I was having fun. Most of what happened I wouldn't wish on anyone. But what I know now is that good things came from it, too. If it weren't for that time as a l'Cie, I wouldn't have met Light or any of the others. I probably wouldn't have worked things out with Dad, either. I wouldn't have known the truth about Cocoon and what it was intended for.
Maybe that curse was something I needed. It's too soon to say just yet, but I think our world will be better off because of what my friends and I accomplished. Maybe mine will be, too.