Stretch your hat over your knee without a hat stretcher 

Sometimes you are away on adventures and your hat shrinks from rain, sun or tragedy. There is an old way of stretching them that will get you out of a pickle.
Place it over your knee and give it a hard pull. Make sure your Panama is soft and moist and it will just stretch. It is an old trick that people have been using for hundreds of years.
Have a look here and I will show you how