100% Polar bear
One afternoon in the Arctic, a father polar bear and his son polar bear were sitting in the snow. The son polar bear turned to his father and asked, "Dad, am I 100% polar bear?"
"Of course, son, you're 100% polar bear."
A few minutes pass, and the son polar bear turns to his father again and says, "Dad, tell me the truth. I can take it. Am I 100% polar bear? No brown bear or panda bear or grizzly bear?"
"Son, I'm 100% polar bear and your mother is 100% polar bear, so you're certainly 100% polar bear."
A few more minutes pass, and the son polar bear again turns to his father and says, "Dad, don't think your sparing my feelings if it's not true. I really need to know... am I really 100% polar bear?"
Distressed by this continued questioning, the father polar bear finally asked his son, "Why do you keep asking if you're 100% polar bear?"
"Because I'm freezing to death out here!"