I'm a genius - NOT!

[baratron]

Also, in a moment of sheer idiocy which could probably be applied to any discipline, including fiction: I saw a reference to a book which I thought was interesting, went to the library website, saw they had one copy which is currently out, considered ordering it, looked up at my bookshelf and... oh.

Apparently, I already have it.

Please tell me you've done this too, so I feel less stupid.