From what I know, Innocense is about not knowing one or more of the horrible truths of the world. It's also about being in a stage of life where one's goal is only to have fun. Nothing to strive for, and nothing that's preventing one's ability to enjoy life.
One might think an individual seems innocent, but the illusion is broken once one observes the individual involved in more grown up actions, or doing something hateful. This goes for children, as well as adults. Children who start to swear, harass or doing mean things to increase their popularity, lose their innocense. Parents can't really be innocent, because they had to do something quite indecent to create a child. Adults which have always lived in a protected enviroment may keep most of their innocense.
These are some of my thoughts when it comes to innocense, but I wonder; if one ignores the awful truth, does one keep their innocense?