User blog comment:CoolJazzman/Was Aizen wife Tosen friend?/@comment-26420452-20131110213749/@comment-11051098-20131116011013

Yamamoto was more than 2100 years old. If we consider that to be 100 human years, the 110 years we know of Aizen's plans would be like 4,5 - 5 years. So no, it's not really that long in a human lifespan.