It wasn't nutil I attended a diversity workshop that I realized the person we passed over was the perfect person.
句子语法结构分析如下：首先该句子是个强调句型:It is +强调内容+that +主语+谓语+宾语+其他
（1）It wasn't until I attended a diversity workshop that I realized the person we passed over was the perfet person可以改为非强调句子结构：如下
I did not realize the person we passed over was the perfet person until I attended a diversity workshop以上是个not .until 引导的时间状语从句；而且强调句型：是强调的时间状语从句
主句：I did not realized the person we passed over was the perfet person
从句：until I attended a diversity workshop （表示主动谓语动词动作发生具体时间）
(A 为主句内容NOT ） ...（B为从句内容.UNTIL .）
表示 A 动作在B 这时间 就发生了：也就是,从句B动作发生了,主句A 动作就发生,否则,就不发生
另外请记住,时间状语从句,是表示主动谓语动词发生的具体时间.