I agree on the Rocket fuel
...thus the trips to NEOs to access a whole lot of water in space! But as Zuppero pointed out years and years ago with water we can make big shielded space stations and space vehicles to travel anywhere we want to. Plus there's a whole lot of kerogens on inactivated comets that can provide carbon and nitrogen that the Moon lacks big time.
I've said all this before and no one remembers...