Sleep could promote many forms of synaptic plasticity, independent of whether the underlying mechanism is synaptic depression or synaptic potentiation. Memory consolidation and brain restitution are important perspectives on the function of sleep that are not mutually exclusive. Synaptic homeostasis hypothesis (SHY) reconciles these two perspectives by proposing that the main function of sleep is to control the strength of synapses impinging on neurons in the cerebral cortex and elsewhere. Most evidence supporting SHY is correlative, and has been collected in one tissue, the cerebral cortex. As sleep is most abundant early in life, and the brain undergoes massive synaptic turnover during neurodevelopment, with an early phase of net synaptogenesis followed by net pruning, it is important to ask whether sleep could benefit synaptic renormalization during this phase of enormous plasticity.