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I dated a guy who was a meth addict. He was delusional. I think it’s drugs.
How anyone can blatantly lie this much, especially when it's this poor, is beyond me. >

If I had to guess, it is a mental disorder. I would assume his upbringing was not ideal and he escaped through lies. He had dreams of grandeur and felt his current life held him back. Just on the cusp but never there (picture George grumping the gates outside the school he wanted to attend.) 
It seems almost identical to Anna Delvey.