Once you start thinking about it in a mercenary frame of mind, then you're finished. You're a joke, because there are too many mercenaries out there already. ↗
Poetry seems to sink into us the way prose doesn't. I can still quote verses I learned when I was very young, but I have trouble remembering one line of a novel I just finished reading. ↗
If you can't think of what to write, tough luck; write anyway. If you can think of lots more when you've finished the three pages, don't write it; it'll be that much easier to get going next day. ↗