The only reason he was even still there when he died is because he didn't have a map of the area and thus couldn't figure out how to cross the river to get back.
Zooming out a bit, you could also say he died because he churned the philosophy of using the aids and crutches of civilization to maximize his hedonistic well-being at all cost - which is maybe a more interesting and ambiguous point to discuss than whether maps are useful ;)