You spend the evening alone on your couch, decline a party invitation or prefer to stay at home instead of going out to a pub or cafe. Some people withdraw, consciously or unconsciously, from social interactions. Sometimes it is just a phase that can help you recharge your social battery. If it is prolonged, however, it can be harmful to your health. People naturally need time for themselves, say, after partying or during stressful periods in their lives. It is perfectly normal to keep to...