The government and Sharia Law determine many aspects of life in Iran as these laws dictate what the people can eat, how they can act, and even what they can or cannot say. Even the people that don't agree with this system must obey these rules as they are laws, so the entire base of Iran's daily life is the Islamic faith.
Beyond the restrictions of the laws, there is more to the culture and way of life in Iran, from a long history that created new foods, dress, and languages to the differing ethnic groups. Plus, today there is a growing divide between the younger and older generations, both of who have very different visions of the future.
Differing ethnic groups tend to have foods, dress, and customs that differ from that of the majority and these differences are generally accepted by the government. These minority groups also tend to be in more rural areas so tend to have more jobs in agriculture and a heavier reliance on the land and other natural resources. The country's majority, the ethnic Persians, tend to be more urbanized and also control most aspects of the government and economy based on both power as well as the fact that they are the majority.
The second huge difference in lifestyle comes between the younger and older generations. Much of the older generation supports, or at least doesn't protest, the current government, but the younger generation tends to see a different future. The youth tend to want a more liberal government and more freedom in numerous social realms. They also tend to be getting more educated as urbanization is occurring and the youth tend to see a future with a new government and a future based on economic progress as opposed to being based on religion.
Although today the older generation tends to live in a similar manner as they have in the past, the younger generation is becoming more urbanized and more reliant on technology. The youth also have a growing lack of trust in the government and it seems every election the youth protest the results, which they believe have been rigged. Technological changes in recent years have also improved communication among the people, adding pressure to the present state of affairs. As one of the youngest countries in the world, numerous changes to the culture and way of life in Iran is imminent, it's just a question of when and how these changes are made.