Sentence Meaning – ‘Ready as I’ll Ever Be’: Does It Mean Ready or Not?

You use "I'm finished" in situations when you know you are dead meat, to indicate you are in some serious trouble. A similar expression would be "I'm done for".

However, there are some situations in informal conversations, where I'm finished is used to indicate I'm ready. Obviously, this is incorrect usage.

I found the definition of "over it" as follows:

1) The expression of a loss of interest in something or someone. (e.g., I thought that Bud Light was great beer when I started drinking, but now I'm over it.)

2) The indication that a negative event is no longer bothersome to someone. (e.g., I suffered for days after she broke up with me, but I'm over it now.)

In that context, it could be that B is still not finished with asking A and figuring out if the person who A is on the phone with is C or not. B still wants to know if it is C. Or it might be that there was some event (probably something unpleasant) that happened between B and C which A also knows about before this phone call, and B still has a problem with that event. I don't know the story, so I'm just assuming though...