Hunger is a mark of health, and the lack of appetite proclaims disease.
The cessation of the desire for knowledge, shows that intellectual growth has ended.
Just so in spiritual life, dissatisfaction is the token of health. "Blessed are those who hunger and thirst after righteousness." (Matthew 5:6) Blessed are the unsatisfied. Blessed are those who long for more and more. The mark of healthy spiritual life is an intense thirst for God; and a deep, passionate yearning for closer, fuller, richer, more satisfying communion with Christ Himself.
The ideal Christian life is one of insatiable thirst, of unquenchable yearning, of divine discontent, wooed ever on by visions of an increase in spiritual life, new joy, and new attainments in Christlikeness. The best thing in us is never what we now are, nor what we have already reached but the longing for that which is yet higher and holier.
[J. R. Miller]

Philippians 3:12-14 ... Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, I press toward the mark for the prize of the high calling of God in Christ Jesus.
Psalm 42:1-2 ... As the hart panteth after the water brooks, so panteth my soul after thee, O God. My soul thirsteth for God, for the living God: when shall I come and appear before God? ❤