https://www.cnblogs.com/tanrong/p/6913203.html

• gameobject.transform,是获取当前游戏对象的transform组件.
  所以在start函数中 gameobject.transform 和this.transform,指向的都是同一个对象。即：gameobject.transform == this.transform == transform

    * transform.gameobject:可以这么理解为：获取当前transform组件所在的gameobect
       所以在start()函数中transform.gameobject == this.gameobject == gameobect

所以他们可以无限的引用下去

意思就是。gameobject.transform == this.transform == gameobject.transform.gameobject.tranform == tranform.gameobect.transform