1. Moving around to touch 4 specific spots at specific times in a small space requires you to learn a new sense of balance. 2. Your legs move much slower than your fingers and much slower than you'd think.
3. Most people like to reset their legs to the centre circle when they start off. While this might be good in the long run, it takes way too long to gain enough leg speed and endurance to get better.
4. As much as you think it might be easy to just jump along to the next difficulty level - do note that foot ratings are misleading, and the graph is equally misleading. Nothing beats actually looking at the step charts and seeing for yourself.
5. Your legs usually have lower DDR endurance than they do from walking or running, due to the slightly peculiar exercise.
6. You're bound to sweat a hell of a lot.
7. Some people use the bar - but chances are if you practice enough you won't need the bar - and you aren't supposed to use the bar anyway.
8. Not moving the mat comes with practice and skill. While it's true that a good mat won't move, it's always true that after some point, you won't move the mat quite as much.
9. You can always use more speed.
10. You always need more endurance.