It wasn't until I began to research this widely accepted career advice that I understood how problematic it really was.
直到我开始研究这个被广泛接受的职业建议,我才明白它实际上有多么成问题。
由 "until" 引导的时间状语从句,在强调句型 "It wasn't until... that..." 中被强调。该从句表示主句动作 "understood" 发生的时间界限,意为 "直到我开始研究这个广泛接受的职业建议时"。