It's easier to relearn gross motor skills than learn them for the first time after injury: Empirical evidence informing the age at injury debate.

The effect of age at injury on outcomes after brain injury has long been debated. Many have argued that the greater plasticity of the immature brain aids in its recovery from trauma, but others (notably Donald Hebb) have argued that early injury can impair the future ability of the brain to acquire new capabilities. This is difficult to assess empirically due to the presence of many age-dependent confounders.