I went to Japantown in San Francisco (just a few blocks away) for some sushi lunch and took my Nikon D90 wioth the Nikkor 24-85 F2.8/4 lens (I find it a fine walking around lens, especially with its moderate macro capability).
So anyway, I was perched in the Peach Plaza (essentially a concrete/stone "park" in the midst of Japantown and saw this couple. Then I saw this young book carrying fellow pass in front of them. I saw the guy with the girl suddenly "perk" at the sight of the book carrier and he started to "track" him. Hence, I took this shot.
I found it reminiscent of the young buck syndrome.