Ever been stuck out camping, fishing, or even at home with a dull knife and no sharpener? Here is a genius and easy way to avoid this happening again. All you need is your favorite old coffee mug. This just might be one of the greatest tricks in the world. 

This is a great tip for people stuck in the outdoors in need of a sharper knife to get the job done. This is so simple, you might never buy another knife sharpener again.