I will try to keep it as idiot-proof as possible.
Paper wallets have been proven not "idiot-proof"... many people have "lost" coins because they didn't understand how to correctly create and/or use "paper wallets".
For a list of the more common issues, refer here:
https://en.bitcoin.it/wiki/Paper_walletNot to mention issues that had nothing to do with being stupid at all, like decay or damage and other errors that are often completely unavoidable.