I finally understand what is happening.
Afterthought added: I really do not understand. My final experiment confused me even more. Also, I manually added cursors to my images because they are not part of the screen capture.
In the following sketch you can see that nothing is fully constrained. All the lines are the same color and the background color of all the enclosed regions are the same color.

When I move the cursor into the outer circle, the bounded area is "selected" and the bounding sketch lines look like they are fully constrained.
When I said "selected" above that is not really the case as selected, such as when extruding changes the selection to a dark blue. In this case you can see that the area where the cursor is located has changed to a slightly different shade, which I assume is just to indicate the bounded region as useful information to the user. Although I do think knowing the extent of the bounded region is helpful when sketching, I do not think that the bounding lines should look like they are fully constrained. This makes it hard to work on the sketch and finish constraining all the lines. Maybe the bounding lines could show in a different color.

More experimentation just proved that my thinking about the color change of the background of the region where the cursor is was done to show the bounded area. However, I just added a constraint to the center most circle and the result is that the background colors change. Now the background of the area enclosed by the fully constrained circle is shown in the "selected" color.

I think that I have come full circle. When the cursor is moved into a bounded area of the sketch, that area is displayed as if the area and bounding lines are fully constrained even though they are not. This leads me to believe that my initial post was an accurate description of a problem with sketching. Regardless of when the cursor is located, when in sketch mode all lines not fully constrained should be displayed as such.