while using one camera lens (developer paper film) &c for a year ( or a week or a month or 3 years ) might
help you become intimately familiar with the stuff that someone might
use to make a photograph ... if you don't have a direction, don't notice, observe or have a connection
to the world around you that you want to photograph it seems like a waste of effort.

cliveH, your teacher's story sort of sounded like the bauhaus theory of learning art ...
its best to have a well rounded education because in the end, whether you use a camera,
chisel, brush they are all the same and feed off eachother.
i can't imagine learning about photography with no knowledge of any of the other arts ..
2d, 3d, even digital arts ... its like writing a research paper without references ...