> I’ve never need to rely on anyone, other than of course normal economic transactions.
That's funny. You are relying on thousands of other people every day, all day long. you just don't realize it. And not all of those are economic transactions there is plenty of goodwill involved. For instance, you rely on other people not to kill you when you are driving. Every time a stranger saves your bacon when you make a mistake, for instance. They don't have to! But if that's your worldview I don't think I'll be able to change it.
> Why would I park my car in a ditch?
I don't think anybody who ever parked their car in a ditch asked that question prior to it happening and afterwards they probably still didn't know. But in areas where there is snow it isn't rare at all to have vehicles do stuff that wasn't quite in the plan. My neighbor in Canada managed to do this with a tractor. Fortunately for him I had a bigger tractor and was able to pull his out of the ditch. And when it was my turn someone kindly brought over an excavator...
Society is a fabric, and no man is an island, not even you. You may have the illusion that you are but from the cradle to the grave you are 100% dependent on other people. Unless you live in the boonies and grow your own food and hunt, but if that were the case you wouldn't be writing here. Speaking of which: right now you rely on me to converse with you.