On the highway I don't always use my blinkers. Often times there will be a car a few hundred yards back, and one a couple hundred feet ahead that I'm approaching fast (a lot of people in my area do 10 under on the interstate for some reason) but otherwise no cars in my immediate vicinity, so I'll just lumber over without bothering with my blinker. I'll pass, go a couple hundred feet past, then lumber over again with no blinker.
To clarify, I always check my mirrors, and I only do it when there is a considerable amount of distance to the nearest car, far enough that no other cars are really affected by the lane change. Is that really so bad? Lately my brother pointed it out to me "kill you to use a blinker eh?". If there is any need to, I do. But often, there isn't really any need so I don't bother (my blinker is really annoying).
Am I an asshole?