You know it's just a bike right?

Living here in Chicago has many perks and one is being able to get around so easily on bicycle. Since I generally can't (or won't) stomach the CTA. I like to jump on my bike and get where I have to go especially while the weather is nice. What I really would like to know is who are these fellow cyclists in a such a hurry? I'm not talking about the guys with 2,400 dollar, super lightweight, aluminum, European editions. The "speedsters" I speak of are these everyday joe's who are in a suit, with their slacks tied up to not get caught in the chain with a basket on the front to pick milk for the wife. Personally I enjoy going at a safe enough speed so I can take in some sites to and from home, feel the wind on face and avoid a possible "dooring" from a cab or anyone not paying attention. I have had riders jump in front of me and ride with a true and concentrated effort to get way in front of me just to be met at the red light. I usually just roll up with the Ipod attached to my ears bumping whatever music choice of the day is and just look at them with a "really?" look. They usually either do the same thing again when the light turns green or look away sheepishly as if they know they just made a vehicular clown out of themselves. The next level of idiocy is the daredevil. You've seen them. Darting in between cars before the light turns green, weaving back and forth through traffic because they're SO FAST! I have seen some daredevils get clipped or wipeout. Is wrong when a small smirk goes across my face. I mean I know my lane (literally) It's just a bike.