I used to neglect the RVs awning when not using it for long periods of time I just left it rolled up. However, this led to a moldy mess on occasion. During heavy rains, water is able to seep in between the layers and sit there. Over time mold spots develop and end up being a real pain to remove.
In the last year or so I’ve made a concerted effort to remember to open the awning after each bout of rain and let it dry out. The habit has resulted in a lot less need to clean the awning and likely increased its overall lifespan.