If you have an emergency in the middle of the night, you can call an ambulance or if it's not a huge emergency, you can call a taxi. The only thing I had problems with when I didn't have a car was when ordering something that arrives with UPS, FedEx or Purolator and since I work, I wouldn't be home so I would have to go pick it up. All their warehouses seem to be out in the middle of nowhwere with sporadic or no bus service. I did eventually figure out that at least with some of them, you can have your package transferred to their more accessible offices where you can pick it up. It's also hard to do bulk shopping. There are definitely places you can't live when you don't have a car and there are certain jobs you can't take. You have to schedule around that.
There's a lot of waiting involved when you take the bus too. Not just waiting for the bus but also going around the bus route which is normally not taking you directly where you want to go. You have to be patient. If time is important, it's better to have a car. Still, a family I saw a documentary about, they were trying to decrease their carbon footprint, they said they found that by spending more time, they gained more time. Taking their kids on the bus, they found that they had a lot more time to talk with them. For me, having a car saves me maybe 45 minutes a day in commuting time. If I have to go somewhere on a weekend or after work, I save even more time since the bus service is less frequent then but I pay for this time. It's a lot more expensive to have a car than taking the bus so up to each one to decide if it's worth it for them.