I know one guy (I eventually gave him the Cut Direct) who was a pathological liar. His parents were slightly well off, but that was because they had one child and both worked long, grueling hours. However, this guy bent over backwards to convince everyone around him that he was part of the leisure class. He was constantly trying to get freebies everywhere when he wasn't trying to convince people that he was rich. Examples include:
-I joined a gym that we were both looking at and he demanded that I open the door for him when he wanted to sneak in, so he wouldn't have to pay for a membership. (A registered key fob was the only thing that could open the door.)
-When we were out at a bar, he buttered up a professor (complementing his clothes/taste) and convinced the professor to buy him shots of ultra-premium tequila.
-He was constantly saying that he "didn't carry cash, only platinum" and so when we were somewhere and he had "maxed his card for the month" he would get a free meal out of one of his fraternity brothers.
-Between paydays, he would run low on funds and so if I suggested a pricier restaurant (even ones that were normal for us to go to) he would say "Sure, if you pay for it" and then whine about how I shouldn't have suggested it. His rationale was always "But you have plenty of money!"
-Stuffing his pockets with free food whenever it was offered in the hallways at school
Examples of him trying to impress people:
-Telling everyone that his dad had an iPad two months before they came out. Of course, he really shouldn't have told me that his dad was technologically deficient immediately beforehand and only had a Blackberry.
-Buying his fraternity brothers pizzas. Apparently, when he pulled out his credit card and bought 10 $5 pizzas, this was all the proof they needed to see that he was "loaded". Of course for months after he would ask for free drinks/food and bring up "That time I bought you all pizza".
-Griping about things like public transportation and whatever smartphone he had. (He broke smartphones like no one's business and would spend hours and hours hashing the details out with a sales rep until he could convince her/him that he deserved a new free one.
As you can see, he was bizarrely driven by what people thought of him, yet he was extremely cheep and obsessed with conning/mooching his way through college.