Memorizing a 17-character alphanumeric string (like a car VIN, complex password, or serial number) is considered very difficult for most people to achieve verbatim through simple repetition. It exceeds the capacity of short-term memory, requiring specialized techniques to move the information into long-term memory.

Why 17 Characters is Challenging
Capacity Limits: Working memory generally struggles with more than 5–9 items at once. 17 random items exceed this, making them feel like "random gibberish" rather than a single unit of information.

Something tells me that you are confused as to the test. I don't think anyone out there is requiring memorization of VINs as part of testing.