It is a rather unusual concept to accept that a child would look around it, see unhappiness and restriction and be motivated to choose that and to implement it in its own life. However, this is basically what happens, except that the restriction and unhappiness is not perceived as negative and is therefore, not chosen directly.
These 'negative' aspects are simply aspects that must exist to qualify the individual for the way of life that has been chosen and that is perceived as being so desirable. The child's decision is not motivated by anything unpleasant. Its total concept of life is that life is to be enjoyed and that it is enjoyed - by everyone...