Lose the drift/thread of something expression phrase
"Thread" in this expression means something that connects the various points of a narrative.
Can no longer understand or follow something, such as an argument, story, discussion, etc. because one has become distracted or bewildered.
Losing the thread of the conversation in a meeting is a common problem, whether you are a native speaker of the language being spoken or not.
Try not to let your mind wander; otherwise, you will lose the thread of this complicated story.
I forgot to stop the movie before going to the bathroom, so when I came back, I totally lost the thread.
The verb "lose" must be conjugated according to its tense.
This expression dates from the mid 1900s.
Daughter: So I really want all my friends to have a great time. I was thinking it would be a good idea to have some candy out on the tables for people to snack on.
Mother: Well, if you want them to really enjoy themselves, candy is dandy but liquor is quicker.