You don't know how you know where you left your own things, but if I do know where a friend left e.g. their wallet or keys, I often do remember why. As if the n

You don't know how you know where you left your own things, but if I do know where a friend left e.g. their wallet or keys, I often do remember why. As if the novelty of the circumstance that allowed me to store the information also caused my brain to store metadata about that memory, e.g. the novelty itself.