The moment you think you can play around because you have it under control, is the moment when you'll learn a costly lesson.
Couldn't have worded it better.
I used to be that guy, in fact, my principle mentioned me in his speech for our graduation; mentioned my driving. If there is one thing I have learned since driving (I know, 9 years aint that long) is never get comfortable behind the wheel. Always expect the unexpected, and always look for danger. I'm still a ***** when I drive and some people don't like riding with me because I still drive like a *****. But I don't ever get comfortable.