Nobody has thought the OP left it on purpose
Or have I missed a post?
Well if it wasn't left in error, the only other option is that it was left intentionally as unwanted.
Realistically, if you were cleaning a completely emptied house and found an item left in a drawer would you think "Someone obviously forgot to get this out of the drawer" or "This has clearly been left in this drawer as unwanted rubbish"?
I would be thinking the former.

