I got kidnapped once, but I remember nothing from it. When I returned my head hurt, like when you wake up from having been sedated. And was wounded but, yeah, can't remember a thing, the droids knocked me unconscious when they got me.

The journals do happen at times to record even when we don't intend to. But if that's the case, keeping them closed should suffice to keep them in the dark, but I think it does nothing.