For him who has conquered the mind, the mind is the best of friends; but for one who has failed to do so, his mind will remain the greatest enemy. ~ Bhagavad Gita
One whose knowledge is confined to books and whose wealth is in the possession of others can use neither his knowledge nor wealth when the need for them arises.
Plough with truth. Plant the seed of desire for knowledge. Weed out falsehood. Irrigate the mind with the water of patience. Supervise your work by introspection and self-analysis.