The Roman Empire introduced new ideas from far reaches, while extending their own ideas to other parts of Europe and the Mediterranean. This empire unified the people and culture in many ways as clothing, foods, religion, and language were all shared. While the tunic is no longer popular, the Latin language evolved into the modern Italian language and the empire's later adoption of Christianity changed the culture to a vast degree, a religion that is still popular today.
Despite the fall of the Roman Empire, the Italian Peninsula remained tied to and influenced by much of Europe. The culture of the region spread to Europe, particularly in the form of religion, while aspects of Europe made their way to the Italian Peninsula. However, sub-cultures emerged and the people grew apart in many ways as local cities trumped the region in importance to many people as family and community remained at the center of the culture.
Even with the Renaissance, little changed in the way of community leadership, however the country advanced quickly in terms of technology and communication, hence rapidly changing the culture. There was a relative excess of money, partially due to advanced technology that allowed less work to be done with the same or greater results. This turned people's attention to the arts, entertainment, and social life when and where it was possible. This ultimately changed culture and the lifestyle in a way that remains common today in Italy and throughout the world.
Despite the advancements, Italy didn't unify for a couple more centuries. With unification the culture and lifestyle continued to change, but the people also became more uniform in many ways. This has continued to change even today as communication and transportation have brought the people closer together. These things have also given Italy a modern society where a walk with cigarette in hand is a nightly ritual and the only gladiators to be found are on their cell phones hawking tourists to get their picture taken with them.