A rant: Use your freaking turn signal!

This post is unrelated to movies in any way. If movies and the entertainment industry are your life, and nothing else matters to you, then please ignore this post. But I need to vent, and the great thing about blogs is that any idiot in the world who knows how to use his or her computer can unleash their pointless rants upon the world. I will keep it short.
Turn signals. Blinking yellow or red lights that indicate when a car is turning a corner or changing lanes. To activate, it takes a mere flick of the finger, a fraction of a second, a fraction of a fraction of energy. Not only is it courteous to use turn signals, but it is also safe. Other people can't read your mind. They don't know you are going to change lanes right in front of them, or slow down to make a turn while they are going full speed, as they should.
So why the f**k are more and more people not using turn signals? It is so easy, so logical, so useful... what makes you so special that you can't apply your finger to that lever that indicates where the heck you're going to go.
This spawns from the other day, where I'm sitting in stop-and-go traffic. The lane next to us moves faster, but also ends, and thus we get the jackasses flying by who then try to squeak in at the last second. Nothing really wrong with that, but lose your turn signal. If you are going to cut in front of me when I've been waiting there for much longer, don't just idle next to me and assume I know you want to come over. Tell me. It's that freaking simple. And I don't know how many times recently I have seen so many close calls, when some dumbass (usually, but not always, in a BMW) thinks it is okay to change lanes without using a turn single right in front of a car that's going 20 mph faster. Just don't.
And that... ends my rant. Do you feel smarter now?