San Francisco is often described as the most cosmopolitan of American cities (excepting NYC). You may find it similar to European cities in terms of nightlife, cinema, cultural activities, and people's eclectic interests. Relative to Europe or Canada, there is little government support of arts or culture but that doesn't stop youth from innovating culture. So you'll find interesting people and interesting activities for entertainment.<p>San Francisco (and Berkeley/Oakland, across the Bay) are centers for culture and youth with adequate public transit and neighborhoods where rents are relatively cheap. The Peninsula and South Bay (the location of Silicon Valley companies) are suburban (wide expressways, shopping malls and office parks) and compare poorly to SF in terms of cultural activities but offer many opportunities for outdoor recreation. Californians tend to choose outdoor activities for recreation (running, biking, hiking, motorcycles) and late-night partying or club hopping often ends early for those who get up early for outdoor recreation.<p>Not many people surf (not as many as Southern California or our neighbor Santa Cruz but of course more than Europe!). It's an option if it's your dream. Surfing for some is an activity on a free weekend or an early morning before work (if the waves are good). For others, it is a lifestyle that leaves little time for career pursuits.<p>It's often said that Americans work longer hours and spend less time enjoying life than most Europeans (if enjoying life is defined as time spent with friends, eating food, drinking, or cultural pursuits). If you work in a startup company, that may be doubly true, as your peers will expect you to be focused on the tasks that will lead to success. You may find that a day at work in the Bay Area moving bits is not much different from the same in a European city. After work hours, you'll be tired but you'll likely find time to try a new restaurant or grab a beer with workmates or a roommate a few times a week. Among entrepreneurs, you will probably not have much free time on weekends and you should not expect holidays.<p>These are broad generalizations, of course, based on my own personal experience, so suitable only for stimulating thought and discussion. Your mileage may vary.