Parents consider that they know how it is necessary to arrive in any given situation, and they seek to pass on the experience to already grown up children. But, as we know, on others experience very few people study. And at adult children the desire to make everything in own way is big. But also there is no wish to offend parents.
To prove the case
It is possible to try to prove to parents correctness of the position. Often it is hard to make it: it seems to parents that they understand a situation better therefore they consider the way offered by them only correct. But if the conversation goes between two adults, let and representing different generations, each of the parties has a chance to be heard and understood.
Try to understand motives and arguments of parents, the reasons which force them to adduce any given arguments. Perhaps, this desire to protect you from possible troubles, perhaps, fear to lose control over a situation, perhaps, their some personal problems which they try to solve, having convinced you to arrive in one way or another.
Having understood the reasons, it will be easier to find arguments which will convince parents of correctness of your position. Try to inspire in them that what they try to avoid, does not happen if you arrive in a different way. Avoid excessive emotions in a conversation: shout, tears and the increased tone of statements – bad arguments in a dispute. Remain are quiet and adhere to a position of the adult sane person, but not the whimsical child, not "to obey the person interested mother".
To agree and make on the contrary
Sometimes it is difficult for not only children, but also parents to keep a "adult" position in a dispute. Representatives of the senior generation not worse than the children can sometimes take offense, be capricious and persist in the delusions. If the constructive conversation does not develop, and mother or the father literally does not wish to listen to you, it is possible to calm them and to stop further altercations. As a rule, parents arrive thus if are afraid to lose the "parental prestige". In this case to them it is not so important, any given situation will how successfully be resolved. They seek to achieve that their "kid" obeyed council of "seniors". Actually, it is their position of "the internal child", but not the adult. Show condescension and patience. Thank parents for a good advice. Try that your words sounded sincerely. Ask questions, specify how it is better to make any given business that needs to be told how to behave in any given circumstances. It will be pleasant to parents that so showed consideration for their opinion, and they will give willingly advice. After you calm them vanity, can arrive with quiet conscience as you find necessary. Parents at all desire will not be able to control all your actions, and to you, finally, the result is important. But nevertheless you should not sweep aside any parental arguments as a priori wrong. Do not turn a deaf ear of their recommendations: perhaps, you will manage to find in them rational grain, and it will help you to make really wise and right decision.