Why is healthcare insurance so much different from other insurance?

Most insurances are to handle for extraordinary circumstances: car accident, death, flood, fire, theft, etc. Why is health insurance for ordinary situations?

To continue the comparison with cars and people: when my car needs maintenance, I pay for it out of pocket and my insurance has nothing to do with it, but when I need maintenance (read: get sick but not life-threatening), health insurance pays for it. Wouldn’t it make much more sense to have health insurance be only for extraordinary situations?

Is it simply a way to even out healthcare costs (like cell phones – free phone up front but higher monthly bill)? Are Americans just unable to manage their money to be able to pay for their own healthcare?