Part of craft of writing comes when determining the best time to reveal information.
I say the "craft" of writing because it's inherently different than the "act" of writing. The act of writing, at least for me, is more like a system purge. You get all of the information out in whatever form it comes. The end of this process will probably resemble a narrative, but it's also most likely not complete.
Infodumps and darling passages overpopulate most 1st drafts because they're necessary components of creating the world and characters. When I type out hundreds of words full of backstory in the middle of a passage, it's usually because that's the first time I've thought of that particular aspect of the character's life. I realized this today as I was reading over 3 chapters of one of my WIP. There's a piece of very pertinent information in there that has absolutely NO business being there.
Not only does it slap the reader upside the head and shout "Look! You need to know this for later!", it interupts the flow of the narrative. So, it's being surgically removed for use elsewhere. The information is still required, but there has to be a better way to reveal it.
Drat those stories that know they can be better than they are. Once they figure it out, they won't settle for good enough, and they won't let me do it, either. Sometimes it seems like I read through something I wrote and passages almost highlight themselves, pointing out that they don't belong. No, I'm not hallucinating :-P, it's just a matter of them "sounding" off when I read them back. The only thing to do is tinker around until they sound right.
Obviously, I'm still a rambling blogger, so I'll stop as not to make anyone's eyeballs bleed from reading.