Where was it said that this was the exclusive focus of that thread?
Ok, there is this thing called observation.
There is also another thing called common sence.
If you take those two and combine them you will have observed:
That people made posts on what happened to them on 9/11.
That people made posts on what what feeling they had on 9/11.
That people made posts on sharing the experience on 9/11.
That people made posts in remembrance of 9/11.
That people made posts for remembering the people who died on 9/11
And from that one can conclude, via common sence:
That the thread is about what happened to individuals on 9/11.
That the thread is about what those individuals felt about what happened on 9/11
That the thread is about people sharing and offering comfort in regard to what happened on 9/11
That the thread is about coming together in memory of 9/11
That the thread is about honouring the people who died on 9/11.
From that one can conclude:
That the thread is about individual stores feelings and experiences on what happened on 9/11 and how their story is different or similar to other peoples stories, so everyone together can honour the people who lost their lives on 9/11.
That was obvious from the content of the thread. It was not said that the thread was exculsively about that, and slight deviation would have been aok.
But what you did was way out of proportion. That is like me coming in here and talking about why some person i know is going to an examn on the subject of "having discussions" next week.
While we are having a discussion (and thus talking about my friend going to have an examn on that subject, so it is vague relevant), it is NOT relevant to the spirit of this thread.
By word alone i could go from this subject to my friends examn. But by spirit and observation and common sence i would see that it isn't really relevant.
If you don't grasp those concepts, i suggest you read up on them.