I fall into the same category as Nick, I feel very strange if I ride without my pack on. I use a small-ish camelback, it usually contains water(obviously), a tube (even though both of my bikes are tubeless-you never know), c02 cart, tire lever, multi-tool, a snack(usually clif bar), and my phone. I cant ever see riding without it. Its always packed and in my truck along with my bike because any second of free time that I have, I will be going for a ride.