I'm wondering how could "AGAIN", an adverb become a key word in a sentence.

If you have a friend facing problems lately and a day later, he/she is telling you that he/she is moody and unhappy, will you ask "what happened again"?

I did that. But this buddy did not tell me what is wrong, saying that I shall not use the word "Again", and ask me his life is it so much of hassle and troubles. Worse still, saying I'm not being supportive.

This is NATURAL ABILITY, another words, COMMON SENSE. It's a NATURAL RESPONSIVE of human. I'm not trying to burden him nor tease him for having troubles "again", but just to know what had just happaned right after previous incident, am I wrong?

I do not know why he is so particular on the word "AGAIN" as my main point of question would be "WHAT HAPPENED". If you are doing summary of essay in dialogue, will you highlight "AGAIN"?

Without knowing what is wrong or what had happened to you, how could I being supportive or gives you suggesstion or the simpliest, being a listener?

The first statement that given by him is only confessing that he is down and unhappy, did not tell me what is wrong. And of course I believe you are awaiting me to prompt the next question, to check and knowing what is wrong.

I'm just wondering, is it "AGAIN" so important in that sentence?

I'm here to ask and to know what has gone wrong, to care, ain't here to fight. Because of this, we brought ourselves into unnecessary conflict.