Kidd,
Undefined,
17 years ago
-answers-
I think I understand your question.
He is asking if you make a topic about something but the creator of the topic does not return to it after several weeks, only to come back then to look over that topic. After s/he has done going over all the posts, he may post in it, thanking everyone.
My answer to your question is;
It depends on your post. If you are asking another question about the same topic, then it might be worth answer. If you are just posting a Thank You to everyone for clearing you up on the subject, then no.
I myself, may go around and answer some unanswered posts, but there are several others that do the samething when they are bored. It may not matter though but it is still fun to go back and see what topics have not been answered and answer them so that the person don't start feeling ignored.