If you've lived in SF for any period of time, you'll know just how difficult obeying parking signs there actually is. There are zones which you need decals for to park during certain hours, but even if you have that decal you still have banned hours which vary per street in order to have the streets cleaned.

Going out of town for the weekend? Make sure you call your friend and arrange to have your car moved once or twice while you're gone. Working late? Better move your parked car in case you're in the wrong zone outside of daylight hours. Having a car required more maintenance than having a cat when I was living there. Even if I wasn't using my car at all, I'd often have to move it three to four times a week just to avoid tickets. I ended up getting about one or two a month while there.