Having the photographic memory that I do, there is one experience (technically it happened yesterday on the 24th) that I don't think I will ever forget for a long time, on several different levels.
I was out delivering pizza in one neighborhood, and there was a car travelling ahead of me. The car ahead of me passed a squirrel that was beginning to cross the street. About 1/3 of the length that I was behind the first car, the squirrel had entered the lane I was travelling in. As the squirrel came into clearer focus, I noticed that instead of having it's bushy tail straight out to go faster, below the tail I saw what looked like another tail as it tore across the street to evade my oncoming wheels.
Sure enough, when I got out, I could see where I had driven through the 'track' that the squirrel left, as evidenced on my tires. A couple of things occured to me after that. Maybe the urge to 'evacuate' on the spot in the face of danger is one of the most primal instincts in survival mode. The loss of the extra 'baggage' perhaps made the squirrel lighter and gain more speed..
...or...
That squirrel was trying to get some extra forward thrust with the explosive diarrhea it had, kind of like a rocket engine.