We were without power for a week in 2011 in the winter and 3 days without power in the summer in 2009. It was no party.
The thing that most people in a city don't realize is that only so much water has been pumped up to where it can be gravity fed. When the power goes out and you drain your uphill reservoir, the water stops running, and that's when the power outage starts to get really unpleasant. At some point the diesel backup generators for the phone system go out too, and then it gets lonely.
People who live in the country with a well, a septic system and a lot more DIY infrastructure have mostly experienced this, but few people in a city have.