I am in SF and felt it. I live on the 9th floor of an 11 story building. The building swayed just enough to notice it. If I didn't know what an earthquake is

I am in SF and felt it. I live on the 9th floor of an 11 story building. The building swayed just enough to notice it. If I didn't know what an earthquake is, I may not have realized it was one. Had I been asleep, the quake would probably not have awakened me.