At the end of the day, breh through out nuclear physicist because he figured the host and the girl wouldn't know what it was and would be amazed by such a complex position. But it backfired. They had no idea what it was nor did she care, and was more focused on personality which he failed to consider.
Dude is a con artist. A grifter. He probably has book smarts, but doesn't know how to apply it. He's also lacking in the social skills department. He's probably use to getting by sounding smart. A jack of all trades, master of none type of guy.