I'm always particular about packing. I roll my shirts, fold my pants, and put everything in a logical place. Heavier items near the bottom when the bag is stood up, items that I'll need first closer to the top when the bag is laid open. To me it's 3-D Tetris to make the most efficient use of limited space and my time finding things while traveling.
DW is almost the complete opposite. She jams things in wherever they'll fit. Her position is that as long as she can force the zipper it shut, it's all good. When she opens her bag at the destination the contents almost literally explode out of it. And while I simply reach into my bag easily retrieving the items I need first, she basically dumps hers out and has to rummage through the pile. Every. Time.