“Nothing I see in this room [on this street, from this window, in this place] means anything.”
The workbook lessons offer a means for gradually letting go of ossified concepts and obsolete frameworks of mind that hinder the reception of Creation. Lesson 1 is the first in a series of perception-changers.
In this world of perception, you tend to categorize everything you encounter according to need, usefulness, or any other type of divider. Since this categorization is different for each person, even though there obviously is overlap among people, it may be clear that the items themselves (that you see on this street, from this window, in this place) do not intrinsically carry the meaning you have assigned to them.
If today’s lesson feels a bit off, you’re right on target! Please don’t feel discouraged. You might want to read the Introduction to the Workbook (ACIM, W-in); it offers much needed encouragement.