Set - 10

The following text is adapted from William Shakespeare's 1609 poem "Sonnet 27." The poem is addressed to a close friend as if he were physically present.

Weary with toil, I [hurry] to my bed,
The dear repose for limbs with travel tired;
But then begins a journey in my head
To work my mind, when body's work's expired:
For then my thoughts--from far where I abide--
[Begin] a zealous pilgrimage to thee,
And keep my drooping eyelids open wide,

What is the main idea of the text?