Before I started flying I had a headset, a fuel tester, logbook, a current VNC, a kneeboard, a Category 1 Medical, a whiz wheel (CR-3), and a whole bunch of books on everything from theory to practical. The only thing I didn't have was a CFS subscription (which is a Canadian thing, I have no idea what the JAA or FAA equivalent of that is). As a student with a commercial license, I can still say I only use my backpack... haha... I've never bought a flight bag, you definitely don't need one. Not at that stage anyways.