It's possible that he genuinely didn't know what to do, that he wasn't smart enough to understand that he needed to point to the other one.

有可能他是真的不知道该做些什么,他还不够聪明,无法理解他需要指向另一个物体

耶鲁公开课 - 心理学导论课程节选

I've never really known what to do with this.

我不知道对此该做些什么。

耶鲁公开课 - 弥尔顿课程节选