My earliest contempt for cyclists began in elementary school, where cyclist kids would just jump on their bikes and ride home while I had to slog through a long bus drive. Cyclist kids felt they were just better than others.
Then in college, cyclists going to and from class on their bicycles were annoying as hell. How many times I would just be walking minding my own business and a dude on a bike out of nowhere weaves through a crowd and just cuts across me nearly hitting me, and at an unsafe speed. I'm sure when you're riding a bike you have no idea how fast you're going, but as a pedestrian it's easy to see how close these individuals were to disaster. What if I had suddenly stepped in a different direction into the path of the bike?
As a careerist adult, cities are no better. I distinctly recall one time in New York City where I was about to cross an intersection when suddenly I heard someone shout, a cyclist was heading straight for me downhill and I jolted myself backward narrowly missing the bastard. He could have easily struck me down.
And then of course on the roadways there is always an anxiety when I see a cyclist. I have to make sure I move aside at least three feet and slow down considerably because I know if I hit them I'll probably be spending time in prison. I don't have a problem if you want to risk your life but you should have to accept the responsibility of your actions all on your own at that point.