i do not find the story unrealistic a other user have comment . actually i know quite a few guy and girl of different nationality that live or have live with their parent not because they could not afford to live on their own but also because it be . convenient . it be not difficult to understand why someone would still prefer to live with his parent under these circumstance he live a he would in an expensive and comfortable hotel ( minus the bill . ) . everything be take care of by somebody else ( clean up after him in the bathroom and laundry and ironing and bill and shopping and preparing dinner etc ) and he do not have to buy a car since he can use his parent car and he do not have to spend his money on everyday life necessity and he can concentrate without a single worry in his mind on whatever pleases him ( e. g. be an eternal student and have a different girl every night in his bed ) . in a few word represent he just spoil . you can see when he try to live on his own that he do not even make an effort and and immediately pre judge that he could not possibly make it on his own . he do not want to live on his own and lose all the comfort he currently enjoy . plausibility of the story apart and i have see the movie three time and each time i find it equally laugh out loud funny a very successful combination of well write dialogue and very good performance by the three lead actor ( especially sabine azema and andre dussolier who be play the two parent ) .