I travel to different locations with an Aluminum body MacBook Pro and tools, cables, documents, etc. daily. So, I needed something that can hold all my various cables and a small computer/laptop toolset in addition to headphones, a mouse, a book on occasion, and nic-nacks suck as adapters, medicine and the emergency energy bar for when I don’t have time to eat. I bought the medium Command Messenger bag to replace a backpack with tons of pockets, but with about the same amount of capacity. I knew it didn’t have as many pocket, but figured I would make do.