> I'd likely be footing the bill for everyone else.

You already are. The rates you pay are based on a pooled snapshot of medical usage of all the people that particular insurer has in that demographic.

The only difference is that with a gov't plan the pool is larger.

EDIT: Actually, I should correct myself. Most government plans have an additional difference - there are no costs based on usage. In a private plan, if you spend everyday at the hospital, you'll feel it in your next premium renewal, with a government plan this isn't always the case, although some countries implement user fees.