Aelar was a badass elven dragon hunter. He encountered the then un-named Ätlän-tã Fælcons when they fell into a dream world to help him fight dragons. This happens every so often, and when they do, they often awaken to discover sand in their underpants. This is likely due to the fact that the first time this happened, they were in a sandy location, and the sand was an indication that perhaps it wasn't just a dream after all. The fact that it continues to happen is most likely residual memory. Even for those that weren't there the first time. Try not to think about it.