Your kids move slowly and are incredibly easily distracted. You could be taking them to the most fun place on Earth and just before you leave, they’d want to play one more game, or splash in a puddle or run around the car giggling for funsies.
You’re not used to this lack of prioritization and it can be annoying. Previously, I marched forward, rushing them into the car, saying no to every stupid (because, seriously, they are stupid) request and time-waster. Let’s just get going, I thought. Why, now, would you want to do x, y or z. You had all day. No. No, no, no, no. Of course, if you say no too often, particularly when they try out their new bartering skills (think, just one more, or just a little), they stop listening to you. Then when you really need it, like, ‘no, stop screaming in the grocery store,’ you’re screwed.