We need a rain cover for the Brain Bag! I've brought this up before and will continue until success. I got caught out in the rain the other day and lost some important papers again because one of the zippers leaked.
This is not a knock against the water resistance of the brain bag. It just that there's a big difference between water proof and water resistant. When you are carrying important papers that need to stay pritine, no amount of moisture is acceptable inside the bag.