I just finished a report that took the better part of two days of my otherwise free time. After 20 years and hundreds of evals, some are reasonably easy. Typically, I need 3 1/2 to 5 hours of face time (interview and testing), then 2-3 hours report time after letting the data knock around in mind for a few days. But once in a while I get one that is a real bear--complicated, but relatively opaque communicators with histories and evident idiosyncrasies that could reflect serious underlying problems... or not. Everything floats close to the borderline of trouble, but not quite over it.
Quality of mental functioning isn't strictly binary, either good or poor. There is a lot of Rube Goldberg action in the mind--many dimensions of functioning with variable capacities, conflicts, shortcuts, compromises and compensations to sort out. A psychologist's evaluation amounts to well-informed data sampling using multiple overlapping methods. Some of the methods are relatively straightforward (most testing), while the interviews are much less so depending on the purpose of the evaluation.
This evaluation was one of the difficult ones. I am glad to be done with it.
After a little brain R&R I'll be on to another one that should be easier.
Heh... you graduate students out there. It can be just as difficult 20 years later. The difference is that when you're done, instead of wondering, you know that your work is good.