I lived most of my life in California. A couple a year that you actually notice sounds about right. If you happen to be in the car, or out jogging, you might not even feel one. Most are just a little wiggle, no big deal. I was five miles from the epicenter of the Loma Prieta quake in 89 (7.1 I think). That was fun. Most of the downtown area was a mess for several years, and I don't know anyone who did not suffer some degree of mental trauma as a result of that one.