So here's a situation that may require some thought (Kudos to @Trizek for point it out):
* I want to answer your question.
* Once I've answered it, I really don't want to get bothered by you again. I'll be angry if you ask me the same question every day (and your response rate will decline).
* But my view might change over time.
* So, for some questions (and not others), it might be worth re-asking me, after a delay that is long enough that it won't irritate me.