"Off Track"

How often do you hear someone say, “I don’t want to get us too far off track…” 

If you’re in a meeting where there’s a stated agenda, there may be a clear line between what's on track and what's not.

But for many conversations that line doesn't exist.   And this preface might simply mean the other person is thinking  “I’ve got something important to say, but I'm nervous to bring it up”.

If they're nervous to express it, that's a sign it might be important.  It might be worth listening closely.