But I deal with this for my parents ALL THE TIME. They manage to delete core, included iOS apps every month or two; in addition to invoking other bizarre configuration options that I've never seen in my life (and that make no sense and shouldn't exist).
Over and over I have to visit the bizarre app graveyard that exists beyond the last iOS screen... the "app library," and restore something they managed to move there. As far as I can tell, relegating an app there from the home screen is a multi-step, long-press-riddled process. How do they keep doing it accidentally? I have no idea.
And several times my mom has ended up with an idiotic keyboard stretched across the middle of her iPad's screen, with no way to fix or dismiss it. Even typing this out right now, I don't remember WTF causes it or how we fixed it.