Are you tempted to delete files showing in Google Drive under 'Shared with me'?
DON'T!
If you do, these files will be removed (will disappear) from the owner's Google Drive and will become 'orphaned'. Other's may have also removed files that you have shared.
DON'T PANIC!
In order to locate these files again, simply open your My Drive using your web browser (Chrome) and paste this command in the search field: is:unorganized owner:me