Well, I can admit to a real "bonehead" hypermiling story... I was heading out of town with my girlfriend and popped into the Post Office to mail an envelope & check the mail. As a new, enthusiastic, budding hypermiler, I smugly turned off the engine and started the turn to diagonal park on the OPPOSITE side of the drive, requiring more than a 90* turn to the left. I was shooting for an open space with cars on each side. I swear I've done this "move" before, but for some unknown reason, I didn't manage to make the turn tight enough. The girlfriend started screaming "YOU'RE GOING TO HIT HIM!!", and I'm thinking "yeah - watch this" (famous last words of a redneck before he dies, right?).
But then I realize I'm actually NOT going to make the turn. At about that point she starts screaming "STOP!". This time, I decide I agree with her, and hit the brakes. For some reason, the power brake reservoir must have been empty (I really don't remember already using them once after turning the engine off, but I guess I must have). So, the brakes didn't respond the way I was expecting, and before I could mash the pedel down enough to do the job, CRUNCH. Yup, I actually hit him. Durrrrr.....
My insurance company said his repairs were around $700. It must have just been a re-painted bumper, because all I did was scratch it, but the girlfriend had a good time trying to get me to calculate how much I would have saved had it been a "flawless power-off park" versus the cost to repair the car I hit.
So I guess John Wayne's quote definitely applies to me here: "Life's hard - even harder when you're stupid"