Wanna know an idiom

[Davy07]

I know there is such an idiom to express that we are talking about different topics right now but just can't remember any.
Thank you in advance.
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Only the Paranoid Survive

[Mister Micawber]

Sorry, Davy-- I need a little more detail. And is it a one-word idiom or some sort of phrase or saying?
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Native English teacher at Mister Micawber's

[Radhika Chowdary]

Hi,Good Morning.I want to know either a phrase or idiom that represents about talks about somany topics.I wil explain the scean that is ,me and one of schoolmet was talked about somany topics in our conversation.When iam telling about these discussion with my collegemate,"i have to tell her that i had discussed somany topics with my school friend but presently dont remember".How to express this with my college friend that doubledcoated text?

[Takenrerei]

Hi there,

I've read your interesting story and I agree with the gardener. There are some people who are like thatin my country too. They usually presume the worst in people.

Anyway what I really want help with are few idioms that normally go with the everyday speech.

Thank you.

Takenrerei

[Davy07]

Hello guys a little bit off topic and let's fly off at the tangent.
Here is the context: While my friend and I are talking about lets say, football but another guy is joining our conversation but he just talks about basketball. so apparently we are talking about different topics. I am afraid a phrase will fit the bill.
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Only the Paranoid Survive

[Cerberus™]

Davy, I still don't understand what it is exactly that you want to express. Perhaps "that is very interesting, but we were actually talking about X"?

Radhika: I don't understand your question either, I'm afraid. Perhaps "my friend and I have discussed many topics, but at the moment I cannot remember what they were".