It seems that, as he grew, this juvenile tree was constantly preoccupied with what was going on behind him. What was that? A squirrel... a bird? Always turning himself around to get a better view. I've seen so many like this over the years, and I could never figure out just what could've caused the interesting anomaly. Until I spent some time just staring at this photo. And now I think I've solved the mystery. What likely happened, was that a vine had wrapped itself around the delicate trunk, in it's softer, baby stage. The tree grew, and the vine dug in, constricting the wood. The vine has since faded away, but has left it's mark, making it appear that the trunk is twisted. Nature does it's own special effects! Hitchcock would be proud.