I do not actually drive below the speed limit to torment impatient drivers btw. As much as I laugh at and/or have contempt for them, and as much as I am very patient and will cheerfully slow down as circumstances dictate and I do not take any chances in the name of saving 3 seconds, my basic thing is to drive, oh, say, 15-20% above the speed limit.
70 in a 60 kinda deal. 120 in a 100.
Now if I learned that an impatient driver saw me saying I drive slow in the left lane and they got their blood pressure up over it, that would lift my spirits.