I forgot if we have ever talked about this.
Simply, I'm trying to tell a friend that I don't remember if we have discussed a topic, and this is what sounds best to my ear. But Google doesn't yield a lot of hits for either "I forgot if we ever" or "I forgot if we have"
I forgot if we ever talked about this.
also sounds perfectly fine. But why can't I get usage confirmation using Google? These seem to be very common phrasing. Or are there more idiomatic ways to say this?