I'm curious as to what is the psychology behind excessive selfishness and shrewdness with money. I've got a great friend who is very popular and a totally sound person in all respects except for when it's his turn to buy a round. He insists, often embarrassingly, on paying separately for literally everything. Coffee, beers, food, everything is hurriedly payed for separately and if there is a chance to save money (if it means being anti-social, or awkward) it will be taken up with both hands.
The thing is that he's the richest person I know, well his parents are yet he is obsessed with money. He is a genuine good person, very selfless and warm to people but as soon as money is involved the atmosphere turns sour.
I am all for being careful with money and being on top of your finances but I've never had a problem with sharing possessions, buying a round of drinks or lending close friends a bit of money. Yet this seems to be a problem for some people and it can be seriously ugly at times.