How do you know if it's your own thing? Maybe some else was doing the same thing at the same time you were, and synchronicity would make it a shared thing.
unless I have an identical twin which I know I do not have then nobody else is doing the exact same thing at the exact same time as me.
How do you know you don't have a doppelganger somewhere? I figured Wither would've been one of the first to wish AD a Happy 26rh?