Postergirl, I do think that times change and people are not as formal / polite anymore as they used to be. Of course, not everyone is that way, but in general, we might have lost at least some of our manners.
In the series of things not to do or say…
In Italy, don’t park in the wrong spot. Tourists might not be aware of this… the parking spots are indicated with lines on the pavement. Those lines have different colours.
Yellow is for disabled drivers, white is free, and anyone can park there, blue is paid. You can park but you have to pay, and pink is for pregnant women. Don’t park in the wrong spot!
Don’t visit the Vatican if you are not dressed properly. A tank top, any flimsy clothing, it’s not allowed when you visit Holy places. Make sure you are dressed properly or you might end up going back to your hotel without visiting anything.
Don’t overcook the pasta. If it’s not al dente, it’s not going to be good - at all.
Kissing? Italians aren’t much into it, but when you do kiss as a greeting, left cheek first. This is a bit uncommon to many, as in most countries it would be right cheek first.