Probably because it is quite often used in such a context and that was where Annie21 first saw or heard it used.
It's me again, with another stupid question - apologetic It's me again -sorry I've been away for a while - not apologetic - sure of being welcome
This sentence is cited by Peter Grundy in his book Doing pragmatics. He said in his book that when we use It's me again as an utterance, it is usually to apologize for troubling someone a second time. What he said confuses me a lot. In my understanding, it's me again can be uttered when someone appear a second time without connotation. That's why I came here for help. And thanks all for your answers.
Not just "appear"; it could also be said in a phone call. If I've been speaking to someone and I remember just after hanging up that there's something else I wanted to tell or ask the person, I'd immediately call back and start by saying, "Hi, it's me again." And there's no apology involved.