In this quote from The Avignon Quintet by Lawrence Durrell, the idea is that experiencing full days and dedicating oneself completely to daily activities can lead to a different way of living. When one is fully engaged during the day and exhausted by evening, it creates a sense of living in the present moment without the burden of past worries or future concerns.

Durrell suggests that this kind of existence allows a person to shed the weight of yesterday and tomorrow, enabling a more immediate and perhaps more authentic experience of life. Being fully immersed in each day brings a sense of liberation from life's usual mental burdens.