Ecclesiastes 12 what does it mean?

The verses in Ecclesiastes Chapter 12 are obviously about aging.
But what is the exact allegation of King Solomon in what he discusses on this work.
First translation is from the Art Scroll version of Tanakh. The second in parenthesies is from the JPS version, which personaly I think makes more sense to me.

When the guards of the house will tremble: (jps version: When the guards of the house become shaky)
  You close your eyes on your soul.
And powerful men will stoop. (jps version:And the men of valor are bent) 
  The  urge to work is diminished.
When the grinders are idle because they are few.  (jps version: And the maids that grind, grown few, are idle)
  Your capacity is smaller.
And the gazers at the windows are dim.   (jps version; And the ladies that peer through the windows grow dim)
   The mood is less apparant.
When the doors in the street are shut.  (And the doors to the street are shut)
   Your thoughts are jumbled.
When the sound of the grinding is low  (jps version: with the noise of the handmill growing fainter).
   You can not hear your heart beating.
When one rises up at the voice of the bird. (And the song of the bird growing feebler)
   The sound of your breathing grows faint.
And all the daughters of song drow dim.  (And all the strains of music dying down)
    Your mind starts to tire.
When they even fear a height  (When one is afraid of heights)
   It is harder to get up out of the bed.
And terror in the road. (And there is terror in the road)
   It is harder to walk and ambulate.
And the almond tree blossoms (For the almond tree may blossom)
   Your body wants to give its last.
And the grasshopper becomes a burden. (The grasshopper be burdened)
    The weight on your body feels heavy.
And the desire fails.  (jps version:  And the caper bush may bud again)
     There is less satisfaction in breathing.
So man goes to his eternal home, while the mourners go about the streets. (But man sets out for his eternal abode, with mourners all around in the street)
   This indicates that at this point, you are considered old.
Before the silver cord snaps.
  Your memory slips.
And the golden bowl is shattered.  (And the golden bowl crashes)
  Your heart slips away.
And the pitcher is broken at the fountain  (The jar is shattered at the spring)
   You no longer can think.
And the wheel is smashed at the pit. (And the jug is smashed at the cistern).
   You no longer can speak.
Thus the dust returns to the ground, as it was,
  Your soul is hardly present.
And the spirit returns to God Who gave it.  (And the lifebreath returns to God)

Utter futility- said Koheleth-
All is futile.