Thus, men, although thirsting after knowledge, having their minds distracted by vain hopes, do not attain to beatitude. The ignorant, addicted to sport in boyhood, to worldly things in youth, find, when they become incapable, that old age is come upon them. Therefore let the soul even in childhood exert itself for its welfare independent of the conditions of infancy, youth or age. This is then what I speak unto you.

In plain words: Prahlada says people want true knowledge but get distracted by empty hopes. They play in childhood and chase worldly things in youth, and suddenly old age arrives. So a person should work for the soul's good right now, even as a child.