Suppose I'm driving down the road, and my son wakes up after sleeping for a while. He really needs to go to the bathroom, and he's likely to go in his pants if we don't find a bathroom really soon. Suppose I'm also in an unfamiliar area with exits that are quite far apart. I don't remember when the last exit was. What might I do? Well, I might pray that the next exit is soon. What would it take for the next exit to be soon?
The most likely way for God to answer such a prayer positively would not involve miraculous transportation of our vehicle to a place near the next exit or miraculous creation of an exit near our current location. It would involve God's orchestration of events such that his awakening and need to use the bathroom would have happened at a point when we were nearing an exit. The prayer is thus retroactive, though it seems not to be on the surface. The same thing can be true of someone asking God for a parking spot to be available upon arrival at a full-looking lot or a prayer that a medical diagnosis will turn up a less severe condition than one might have thought it would turn up (while still being a true diagnosis). People pray like this all the time. I've given three examples. It shouldn't be too hard to think of more.
This means there's a kind of prayer that people engage in fairly frequently that is a sort of disguised retroactive prayer. I've argued previously that retroactive prayer makes perfect sense as long as God has perfect foreknowledge, and this post isn't to repeat what's already in that post. It just hadn't occurred to me that prayers like this are retroactive. Retroactive prayer is much more common than I'd thought.