What is the secret of the melodious madness of the skylark?

The secret of the melodious madness of the skylark is that the skylark, is never exposed to the worldly sufferings, sorrow, pain and worries to which human life is subjected. Human beings are extremely absorbed in the activities pertaining to the 'past' and apprehensions of the 'future' and so they can never be in 'present'  in which skylark seems to dwell.