I don't have any better 'watch out for the cars' ones than those already posted, so here goes a goof on my side:

I had just finished a long climb (one of many...) on a randonneuring brevet. I was looking forward to this particular hill ending, since it also included a whopper of a downhill right after it, versus the gradual up-downs that came previous. So here I was, whizzing down a lightly traveled mountain-side highway at 40mph. This was an overnight ride, and because I had a ton of junk on my saddlebag I hit my brakes on a moderately sharp right curve to slow down a bit... and the front tire began wobbling. A lot. I noticed this in the previous hills, but since I wasn't going nearly as fast I didn't make too much of it; obviously the front brakes were off center from transporting it to the start.

There were few enough cars on the road (hadn't seen one for a couple mins at that point) that I figured I could get by making a wider turn into the left lane for this turn. This was already a bad idea but I really did not have a choice, I wasn't going to slow down in time with just the rear brakes. I figured, if I stop after this turn and fix this I should be just fine. Well, Murphy's Law likes to strike at the best of times, and sure enough as I made the turn I was facing a line of cars maybe 200 feet away while on the wrong side of the road. Now it was do or die, and I managed to make a sharp turn back into the correct side of the road w/o falling. I stopped, noticed my brakes were off center by a quarter of an inch or so. A quick adjustment later I was riding w/ no problems.

So what did I learn? Check your bike once in a while for maintenance issues. All the vigilance against problem drivers out there is not going to help you when you're thrown into a high-speed lane when you (and the drivers) least suspect it because of a mechanical failure. I consider my situation as extremely lucky, considering what could have been the outcome.