The art of writing from a memory and experience.
When we are inspired by an event, person and experience, we can write immediately about it. If we postpone, we'd have to rely on our memory of the experience rather than the experience.
The quicker, we reflect, the better we get a lot from the event, experience. Whenever I postpone reflecting through writing, I tend to lose a lot of details and the way I memorize the experience do not let me to dwell into a deeper reflection.