It really is the only way to drive in Italy...
Nobody is polite. Rules are optional. Everyone is.... I was going to say aggressive, but assertive is a better word.
So ironically, if you drive nice, follow the rules, stay in your lane etc, you end up disrupting the flow of things.
Like I said on FB... Pick your gap, aim, floor it. Scrape the bits of Vespa off later. You'll end up fitting in nicely :D