This is probably the thing people understand the least about the left lane, and I bet this guy is one of em.

It doesn’t matter what speed you are passing, as long as you are passing (and of course if you are barely passing youre a dick).

But not because im passing 10km/h faster and you want to pass 30km/h faster, that I need to move out of the way. Flashing your lights and putting your blinker only makes me want to pass slower. The left lane is not reserved for the fastest driver on the road.