A rather cliche saying comes to mind... when in Rome, do as the Romans.

From what I have seen, the Italians dress very neatly and conservatively. I feel that it is a matter of respect to emulate the manner of dress and behaviour of a place that you visit. I would not even consider jeans 'correct' to visit some of the historic sites. I may not be Catholic, but dressing neatly and conservatively to visit the Catholic historic sites in and near the Vatican seems like a no-brainer. It's just respect.

On the flip side, I wouldn't dream of hanging out in a working-class area in clothes that are obviously very expensive, and I remove most of my jewellry as well.. I feel that the flaunting of wealth and privilege is equally distasteful and insulting.

You know, one of the great truths that I learned in my years of study of wildlife management and biology, is that one of the most important parts of an experiment involving the observation of a living thing, is that the very presence of the observer changes the behaviour of the observed.

Applying this to travel, if you want to really appreciate the people and places as they are, you must make an effort to blend in enough that the locals don't react to your presence.

I live in an area that becomes a tourist zoo at some times of year, and us townies really act differently -and not in a good way- when faced with ostentatious, demanding, loud tourists in their expensive cars. The tourists don't see us as we really are.

Do you see what I am getting at?

Fine, wear your dumb shorts... but recognize that you are doing yourself a disservice. This teacher is wiser than you guys give her credit for, even though if that were I, I would have just come out and said, no shorts, it's disrespectful.