In this brief chapter, the question is discussed whether acutely stimulating adult hippocampal neurogenesis would indeed be a meaningful medical intervention. This is generally assumed. However, the degree to which new neurons are lastingly integrated into the neuronal network is not only a matter of the acute availability of a pool of precursor cells and immature neurons but also (and more importantly) specific survival of the newborn cells. Under normal conditions, only a small percentage of new cells terminally differentiate into new granule cells. Across the lifespan, a sufficiently large pool of recruitable cells must be maintained, rather than focusing on achieving acute peaks of proliferation, because these new cells can only build upon what is already present. Consequently, maintaining youthful levels of precursor cell activity in the dentate gyrus is a prerequisite for lifelong, cellular plasticity.