The devil is very envious of those people who pray and uses all sorts of ploys in order to stop them doing so. So when the demons see that you’re ready to pray properly, they remind you of supposedly urgent things. Then they’ll make you forget and urge you to go looking for them. Since you can’t remember what they were, you become worried and sad. Then, when you return to your prayer, they remind you again what you were looking for, so as to turn your mind back to them and so that you’ll forget about your productive prayer.