From someone who has had a broken jaw, and was wired shut for a month+... You want chin protection for sure. Especially when youre just learning to ride.
Not that a liquid diet, massive amounts of pain killers, losing 45lbs in a month, having to have someone check on you when youre asleep so you dont choke on your own saliva/vomit, several thousand dollars in medical bills, having to relearn to eat/speak, and a daily risk of severe infection isnt fun...
Oh, and if you think the part where your jaw shatters like glass wasnt enough awesome for one lifetime, wait till they remove the wires...
And its always a blast when its really cold out, and the metal plates holding your jaw together feel like ice in your face.
Just sayin...