Who among us has never had the experience of living of minutes long, that he had the impression that time has stood still, or on the contrary, to hear the time to escape, fly, and magare to experience regret? Are common situations in the life of all, they prove that the perception of time is almost never objective, that is, corresponding to the real movement of the clock hands, but as it is often influenced by our moods and our attitudes against what we are experiencing. The student who at school is concerned interrogation and waiting for the end of the hour as the liberation from a nightmare, the minutes will live as eternal; as well as the girl waiting for the appointment with the love lives waiting as long as the time you spend with him will seem too short, it will pass in a flash. What causes this? First, as already mentioned, it depends on our attitude towards what we are experiencing: if we are doing something that interests us, which attracts our attention, that we like, then time will seem short, if on the contrary we get bored , we do things that do not arouse particular interest, or even there are unpleasant, time will seem to pass ever, we live it as much longer than it is. Another factor that influences the perception of time is the attention that we pay to its flow: the more attention you pay more the amount of time we seem long. But when we turn in thought to periods that we considered very long as we live them, because no particular event had come to break the monotony, they seem in much shorter memory; on the contrary, a trip or a vacation interesting and pleasant, experienced as very short, in the memory will be much longer. So, almost paradoxically, we can say that working having many commitments, we shorten the days and we lengthen life.