Take this test of your awareness skills, then come back for discussion. Spoilers/hints are below so take the test first before you read any further!

A couple of people already mentioned this test in
comments elsewhere, and I posted it to CommuteByBike yesterday. I passed the test and saw that "surprise ending", but I knew what to look for because I was familiar with the
UIUC perception study from a few years ago that Sue mentioned.
Read the complete post at http://feeds.feedburner.com/~r/Cyclelicious/~3/250213834/test-your-awareness-and-perception.html