3:08 PM, Sunday July 4th 2021
This course isn't something that promises to have you develop a certain amount of skill after a specific point, lesson, or exercise. Instead, it introduces you to concepts, and at specific points (like the box challenge) provides you with a bit more of a focused amount of work to help push you more solidly in a particular direction.
So that is to say, there's no expected "level" a student is going to be at once they finish Lesson 1 and the box challenge.
When it comes to developing a grasp of 3D space - that is, the ability to better understand how to manipulate forms in 3D space, and then draw them on the page, that is the main goal of this entire course - not just the first part. We go on to explore this through all of the constructional drawing lessons, from 3 to 7, as these have us continually thinking about how the forms we draw exist in space, and how they relate to one another within that space.
Long story short, no. You're not expected to suddenly be able to rotate boxes perfectly by the end of the box challenge. It's one step in a long journey, and this course as a whole is more about teaching students how to train and practice that stuff - it doesn't promise that you'll be at any particular stage at the end, and the expectation is that you'll still be practicing these exercises continually as you go forwards.
Lastly, don't forget - in Lesson 0 I mention that you should continue to practice the exercises you encounter as part of a regular warmup routine. That includes drawing freely rotated boxes and checking their line extensions.