A father Polar Bear was out walking on the ice with his son. His son turned to him and asked "Daddy, am I really a Polar Bear?" "Of course you're a Polar Bear" replied the father, "you've got white fur, and a shiny black nose - of course you're a Polar Bear". A little while later, the son asks again, "Daddy, are you absolutely certain that I'm a Polar Bear?" Sighing, the father bear says "son, I've told you before - you've got white fur, a shiny black nose, you eat seals, and you've got huge sharp claws - of course you're a Polar Bear!" A few more minutes passed, and the son asks again "Daddy, are you certain I'm a Polar Bear?" Exasperated, the father tries once more to reassure his son. "Son, I've told you over and over, you have white fur, and a nice black shiny nose, you eat seals, you've got huge sharp claws, and you've got big fangs - of course you're a Polar Bear!" "But what makes you unsure?" asked the father. The son replied, "because I'm f***ing freezing!!"
(with thanks to Angus-me-Coatup !)