To define the customer sector to which we are referring, we will describe a certain division of individuals, on the basis of their lifestyle and family relationships. I believe that this division may coincide with that classical division which, I suppose, we have all seen at some time of "the empty nest", "the full nest ", but it will also attempt to consider attitudes and behavioural patterns of the parents with respect to their children and not simply the existence of the homes and whether they are "full" or "empty". This division will allow us to orientate ourselves and indicate the point of departure from which we will try to explain or understand the world of youth and our feelings towards this collective group. I believe that people have 3 lives and, in the western world, these correspond to the three generations through which a person will normally live: children, parents and grandparents. To put it in a different way: a person comes to assimilate all essential experiences, comes to experience all types of sensations, in an approximately 25/30 year cycle. This cycle has nothing to do with economic cycles, nor with the conservatism/liberalism cycles which alternate in democratic western countries, but with the fact that every 5 to 30 years a new generation becomes part of a person's life. Children cause people to relive anew all experiences. With the children, one learns to speak again, to eat, to dress, to discover all things, all elements, all feelings, all lustrations, etc a process which repeats itself again with the apparition of grandchildren.