Sleep is of paramount importance in our life: lot of it is spent in sleeping; whose quality heavily affects our awake remaining time. A newborn spends most of its time in sleeping, probably completing its maturation when out of the mother at the latest compatible moment with relative dimensions in delivery. The other necessary function is nourishing, now that the direct umbilical maternal feeding is lost, substituted by her breast (or surrogate): thus the first ordering in sleeping is just to interrupt it when needed in order to nourish, which is at least at the beginning every few hours, the baby needing enough, being not yet able to get a lot each time.

The natural order, at least at the beginning of our extra-uterine life, is thus multi-phasic, like it is believed it always was with a genius like Leonardo, and some do experience also in adulthood either by elective choice or necessity. Only, being the baby need of sleep much higher than for a grown-up, the amount of sleep in each cycle of few hours is much more in babies that awakens, instead prevailing in Leonardo-like adult sleepers. On the contrary, usually, getting adult, the length of each cycle tends to increase, through a twice-a-day uneven period (early afternoon nap) toward the daily period, imposed by social working habits, often decreasing the sleeping phase to the minimum compatible with well-being in order to enjoy day life at most. But with certain jobs, like guard soldiers, a different habit needs to be imposed at least in defined circumstances, like sleeping four hours each shift of six, in order to be awake and vigilant the remaining two ours of the shift [1].

All that said is of course well known: it has been recalled here just to remind that if some order in sleep habits is probably useful, when not even needed, in order to get most profit of it, a great flexibility is typically observable not just inter-subjectively but even at a lesser amount at least in short term - even intra-subjectively; and when one is almost exhausted, even just a short nap is restoring! One needs thus to be very careful in talking about sleep disorders, not risking to try to impose a rigid standard not needed or even obnoxious: probably the unique meter in order to judge about sleep order is health and wellbeing of the very one person, also complying

Whit her/his social duties, including work. Nevertheless, with aging, most of us, even great sleepers not just in babyhood but also in adulthood, do experience at least partially unsatisfactory sleep, both in quantity and quality: sleep apneas, for instance, are nowadays recognized as a quite diffuse phenomenon, mostly unconscious until a polygraphic recording reveals them in their true dimensions. Therapies do exist, not always satisfactory for everybody. It is quite difficult to prescribe a generalized remedy - like indeed in almost every disease: the quest for a personalized medicine is thus obviously strongly prompted in this field, where it is even less easy than in other to arrive to an "aseptic" prescription, even after instrumental diagnosis and monitoring. Chemo-physical aspects do in fact interplay in this case with psycho-social ones in an even heavier way than in other diseases, thus probably asking for a full approach to the whole person instead than only - but obviously together with - the still important specialist hint. When finally we devote time and attention to listen to ourselves, it turns out that mostly habits - together with therapies when needed - are implicate in recovering an order - probably not exactly the same all over our life - compatible with the increasing aging (and often weight and lack of physical exercise) implied by our present life.