Where did I get them from?

My nephew thinks I'm a pencil thief; he believes that I am systematically depleting his stock of supplies. Every time he sees me with a new pencil or pen he wails: "that's mine!" just as he did moments ago to the point of tears. I hotly denied that my pencil was his, it was mine as I had found it in my room. Just like the other ones. But then on reflection I have no idea how I have acquired the pens and pencils that I have as I have no recollection of buying them, but I have a little tub partially filled with all types of stationery. Hmm, could I have a problem? Am I an unconscious kleptomaniac with a particular weakness for children's pens and pencils?

To be continued.......