Our use of reference in this course is primarily as a source of information. It informs all of the choices we make in terms of which forms we add, where, the nature of those forms, and so on. But, in executing the marks that we need to create those forms, we will inevitably make mistakes - big ones, small ones, whatever - as a result of us not being perfect robots, and thus not being able to, as beginners, make exactly the marks we intend.

Thus, we deviate from those references, and must carry on, upholding the structure we're building, while still applying the information from the reference. You are thus bound by your construction, as it is built up - bound to adhere to that structure as it is, and not to take the kinds of shortcuts that would bring us back in line with the reference, but at the cost of the structure's solidity.

You will of course always be pushing yourself to observe more, to invest more time there - but it all comes down to understanding what the purpose of that observation is. To see things as they are, and more importantly to identify how they can be broken down into individual pieces which can then be used to reconstruct the result.

Common signs that you're not observing frequently enough throughout the process and instead relying on memory is when things get vastly oversimplfiied and cartoony. Signs that you're observing fine but perhaps not allowing yourself to dig into those later phases where we find the smallest of our relevant forms, could suggest that you're simply cutting yourself short too soon, and need to invest more time into observing in the later phases of construction.

Ultimately, reference is extremely important - but as with all things, it's about the role it plays, and how it operates as a tool for you to achieve your ends. Or in this case, the exercise's ends.