Inner wealth is different from the material wealth in which our life depends to live every day all our whole life, such as house, food and so on. Inner wealth is something which we cannot see and touch. That is our knowledge which can be divided into two kinds.
One kind is special knowledge, such as doctor, plane pilot, builder, farmer, and so on. Another kind is general knowledge in every field. By the combination of those two classes of people, an amicable society has been formed.
Material wealth is very realistic. We need a house to live, food to eat, without which we cannot live on our life. Therefore, we have to turn our inner wealth to material wealth as a goal of our life.
Inner wealth is very safe which nobody can take it from us, but material wealth is different. Everybody is waiting for a chance to take material wealth from us if we are careless to protect it. If you have no wisdom, your material wealth can be snatched away by many cheaters around you.
For young persons, you should seek more inner wealth, but for old people, only material wealth can protect them to live on at their old age.
Since young people have no experience to protect their material wealth, it is the only way to seek inner wealth, which is the special knowledge that young persons should aim at.