What is in the backpacks live pros carry with them?

[pfapfap]

I'm not a pro, but I'm sort of young. I tend to keep sweatshirts, first aid kit, a book, sunscreen, toiletries, ipod, headset, camera, phone, keys, notebook, water bottles, bike helmet, and whatever else I happen to be carrying. Men don't get to have purses, and I hate bulky pockets.