A health condition that persists, when someone says something that is completely full of shit. The lie is so rediculous, that people actually are led to believe that the person telling it is suffering from a mental illness, rather than being a total bullshit artist. While Papap's Disease was originally thought to have afflicted the elderly, such as a grandfather, certain traits have been noticed among cousins.
For example, a child saying, "It was nice playing cards with you yesterday, Grandpap. Can I come over next week, and play again?" The afflicted grandfather responds, I haven't played cards in over 20 years. It causes too many fights."
Traits among cousins can be seen in the following statement: "Yo boss, I don't think I'm going to watch that much football this year."
This guy's so full of shit, he has Papap's Disease.