Reconstructive Memory Theory
From PAPP

Disclaimer: This theory is extremely schizo. Despite that, there is some chance it is true.
One of the most common occurrences in Papp lore is misrepresentation of the truth and of the past. The abundance of Papp lore and the extensive lying that he has done are some of the main reasons why Papp lore has been documented.
Originally, it was commonly believed that the reason for this behavior was simply out of the desire for attention, or due to his need to compulsively lie. However, the reconstructive memory theory is a more schizo, but also more logical answer for why he acts like this.