You're not an idiot. You're just a bonehead.

你不是白痴 你只是沙雕。

When he laid the floor in the kitchen, a more heavy-built colleague with a missing little finger on one hand, after calling him a bonehead three dozen times, showed him how to take proper measurements.

当他给厨房铺地板的时候，一个壮实且少了一截小拇指的同事在叫了他三十几遍“笨蛋”之后，教会他如何正确测量。