During communication with other people it is quite often possible to hear such words which it is impossible to call simple. It, perhaps, words of some literary hero or hero of the movie. If these words are known to much, then they receive the status of a popular expression.
The popular expression (or a familiar expression) is a steady phraseological unit which appeared from some cultural or references. If these words are very expressive and memorable, then they receive the status of a popular expression.
Often many the source of this popular expression is not understood any more, but words remain unforgettable. For example, the familiar expression "After us the deluge", but very few people will remember that these words were told by the marchioness de Pompadour is known to everyone. Such examples it is possible to give great variety.
The concept "popular expression" very closely intertwines with another, related to it - "phraseological unit". The phraseological unit is a set verbal expression too, but, unlike a familiar expression, the phraseological unit not always has the reference. In addition, the phraseological unit is an indivisible, separate lexical unit that cannot be told about a popular expression. The popular expression can possess the different period of life. It depends on that, the level of cultural development of any given society is how high, as well as from what speed of introduction in cultural use of new trends and elements. As an example it is possible to remember a popular expression "It is good to live, as they say. And it is good to live - even better!" from the movie "Caucasian Captive". This expression is often consumed by people of old generation. It is unlikely the same phrase will be able to cause the same positive emotions in youth which possesses other value and cultural reference points. Popular expressions are the cultural phenomenon which demonstrates high spiritual development and the phenomenon of cultural memory. Cultural memory is the phenomenon connected with continuity new generations of traditions and customs of ancestors. At the developed cultural memory there should not be doubts that the new generation will treat with disrespect events of former years.