Why did this person flash their headlights at me?

I was heading home from Atascadero today and was in the fast lane in California going 71 miles per hour (6 miles over the limit). This rude person in a white Audi pulls up and is several hundred meters away from my car. When I was driving before, she was not there. I always check both mirrors and indicate to

I was heading home from Atascadero today and was in the fast lane in California going 71 miles per hour (6 miles over the limit). This rude person in a white Audi pulls up and is several hundred meters away from my car. When I was driving before, she was not there. I always check both mirrors and indicate to other drivers once I am about to change lanes. She flashes her headlights at me once, and then does it several more times. She had to have been going 75 miles per hour. I was driving the speed limit in Southern CA, and ignored her gesture. There was a truck besides me that was trying to get past another vehicle in front of it. The woman flashes her headlights several more times and I ignore her, because to me I cannot do anything about it. She roars into the middle lane, sneaks around the large truck and glares at me and starts yelling. I shrug my shoulders and then, instead of getting in front of me which I thought she was going to do, she gets into the far right lane, gets off the freeway, and drives onto the overpass as I drive underneath? Was I in the wrong? I am usually almost always in the slow lane or the middle one, but was traveling downhill on the freeway. Help me out please. She pissed me off.

Other answer:

Dylan:
You were doing 71 in the far left lane!! Really, if you are not going to keep up with traffic change lanes to the right. If you have traffic coming up behind you and there is no one in front of you slowing you down, then change lanes. It is not your place to enforce the speed limit by puttering along a mere 6 MPH over the limit in the fast lane in California. You are being a road hazard.
ANDY:
Hello

There is a Driving Lane. Then a Overtaking Lane Then a Overtaking Overtaking Lane
You were in the Overtaking Overtaking lane, Lorries are not allowed in it and are restricted to 60 MPH.
You have every right to be there at 70 MPH as that is the legal Speed Limit. The person behind was trying to get you to go faster and you did not (Which as you are in front is your option) I suspect they knew they were getting near the exit they wanted and didn't want to drop back behind the lorries (Which is what the should have done)

Andy C

Dimo J:
Flashing of the headlights is the normal method to telling someone to move their *** over to their correct lane.

There is no such "fast lane"

Speedometers lie. At an indicated 71 mph you were probably driving 64 mph. You can use an app with your smartphone to verify your actual speeds.

If anyone passes you on your right, you are breaking the law: http://leginfo.legislature.ca.gov/faces/…
21654.(a) … at a speed less than the normal speed of traffic …shall be driven in the right-hand lane….

I have seen vehicles pulled over by the CHP for driving in the left lanes.

g:
You were simply hanging in the passing lane. The woman in the Audi was rude but she did have a valid point. Don't hang in the far left lane on a highway unless you have intentions on passing slower vehicles.
Ron:
The left lane is a passing lane and only a passing lane. If you aren't going faster than the vehicle to your right, then you need to move over. That being said, she was being her usual impatient self. No doubt she would have exited at the last minute from the far left lane if given the opportunity. I call this the "California exit".
OwlTrading:
You are a visitor to the U.S.? Stay in the right lane as much as possible. Try not to let rude drivers affect you. Walking they probably would behave much differently, something happens when people are in their car. Anyway, don't feed the drama. Take care.