Because a newborn will develop so rapidly over the first two years, Colgate crib mattresses are designed to cater to an infant’s growth. We as adults are already fully developed and therefore choose a mattress for the most comfortable sleep. With an infant, however, the mattress is more than a sleeping surface, it is their growth and developmental center. During sleeping periods, an infant needs a firm, flat, even surface to maximize his or her development. This is particularly important when the infant becomes more active in the crib. They need the firm surface to provide the resistance as they begin to push up, turn and eventually stand in the crib. A solid mattress base provides the resistance necessary for developing and strengthening muscles. Ask yourself this: Is it easier for an adult to walk on a wooden floor or a waterbed? That is the same concept when an infant begins to stand in the crib.