User blog comment:Eduardovongola/Matsumoto's Past and It's value to the History/@comment-5882223-20140122070704/@comment-11446176-20140122072627

She was still a child when Aizen was experimenting with Hollowfication - which is what drove Gin to try and take revenge.

As much as things are "turned on their head", it doesn't quite happen THAT drastically.