It was her lack of confidence that surprised me --> What I found....................................................

$\text{It was her lack of confidence that surprised me.}$

$\text{⇒ What I found is was her lack of confidence that surprised me!}$

$\text{Cấu trúc mệnh đề danh ngữ:}$

`That``/``Wh e th er``/``WH-question + S + V_1 + O + V_2 + …`