When I went to my first conference, I had no idea what I was doing. I tried to read up on tips, which helped, but didn't prepare me 100%. I went to the conference armed with business cards, cell phone which I as a camera, a back-up camera, and my laptop. I definitely underestimated how much I would be using my tech devices. As a techie, I was a total failure. My cell and camera were consistently dying and with back to back events, I couldn't get them charged in time. I didn't have time to go back to my room and find a charger! I needed to be around. LOL, I learnt my lesson though and have come to love external chargers.
