I read over some of his additional posts on his personal Facebook page. I think that the dentist story is true, and that what he says about his background is also true. He would have to be quite the creative writer to make up his entire GB page. I also think he is an insufferably arrogant little twit.
One thing that particularly annoys me is that he asserted that illegals don’t take away from others. But ofc his Stanford story disproves this, for fewer than 10% of applicants are admitted at places like Stanford. He is taking a space that is denied now to many US citizens and other LEGAL applicants.
Let's say his story is true. So he writes about how mean Mr. Dentist was. But reading between the lines I'd bet money he was an insufferable patient.