What is the meaning of the "The Lazy Mist" by Robert Burns? How can I analyze it?

The main theme in "The Lazy Mist" is the ephemeral quality of life.
In the poem, the narrator's attention is drawn to the "lazy mist" and how it heralds a change in season. He decides that the mist reminds him of the stealthy advance of "Autumn to Winter." 
More than anything, the narrator laments that the "forests are leafless, the meadows are brown, and all the gay foppery of Summer is flown." The seasons are capitalized, demonstrating their importance as markers of time for the narrator. Essentially, the passing seasons are metaphorical for the swift advance of the narrator's years on earth.
The narrator tries to remove himself from the phenomenon of passing time ("Apart let me wander, apart let me muse"), but his efforts are in vain. Time flies by quickly, pursued by Fate. The narrator laments that he may have lived his life in vain, and he grieves that so little time is left to him on earth ("How little of life's scanty span may remain"). 
However, he is helpless to change the fact that everyone must die. The narrator anguishes over the fact that Fate (which appears to hasten death) will rob him of the progress he has made in life and the connections he has formed during his years on earth. He laments the futility of a life that amounts to such loss and argues that, if life is to be worth living, man must have something beyond his existence on earth.

How foolish, or worse, till our summit is gain'd!And downward, how weaken'd, how darken'd, how pain'd!Life is not worth having with all it can give,For something beyond it poor man sure must live.