Designing: Work or Fun?

In my 14 years as a UX-Designer, I have been involved in a series of projects, some of which really appear like fun, especially to those outside the design team.
Processes such as shadowing a potential user, or acting out their day-to-day roles can look funny because of the designer's lack of expertise in performing said task or operations.
However, such experience of being there physically, breathing the same air as the workers, trying the same work tools or interface as the worker gives the designer a good modeling clay for creating a perfect solution to the problem.
I can relate to this feeling from my experience during the Flashback Project process, where I played the role of "fly on the wall" and shadowing process plant workers at Carlsberg breweries in the city of Frederecia, thereafter, Danfoss wastewater processing unit and Soenderborg city's wastewater processing plant.
I saw, I smelt, I learnt.