The core explains it adequately I think, it just hard to understand.
First off you can only keep track of the human world when you are traveling directly between two points, both of which are already formed 'active' gateways between the human world and the hedge. So if you start on earth, and your destination on earth, you may be able to keep sight of the world, but if you start in faerie, or from a hollow, or if your destination is somewhere in the hedge, etc, then you won't be able to since you have 'turned your back on the world.'
The basic mechanic for traveling in the Hedge is a Clarity roll. When you enter the hedge, roll Clarity - if you succeed, you make it to the active gateway closest destination with no problems.
If you fail you have four choices (again, assuming both origin and destination are on earth with no sidetrips):
- head back the way you came.
- make a gateway back to the world right there.
- follow the path, but lose sight of the human world.
- go off the path and keep sight of the human world.
After which you roll Clarity again and see if you got a success, if you do you make it to your destination gateway and return to Earth.
The last option is the most interesting, because you're now traveling through the Hedge, with no hope of finding a path. You'll either reach your destination, at which point you find a gateway and hop through, or you'll decide you have to find a path, in which case your destination has changed and you lose sight of the Earth.
Actually I'm not sure if you lose sight of the Earth when you decide to go off the path, that's up to you. I suppose you might also lose sight of the Earth if you roll a critical failure on the clarity roll (easier than it seems), or if something distracts you enough, but there's no rules for that. If your 'goal' changes from finding your gateway to dealing with some situation you discover, or if you roll any critical failure, are both good guidelines.
So lets say you see some hobgoblins being punished by some slaver, if you ignore them and continue on your way, your goal hasn't changed. But if you stop and free them, it has. On the other hand, if the same hobgoblins are actively blocking you, you can defeat them and pass by, but you can't stay to celebrate or go on any quests for them or your goal will change and correspondingly you lose sight of the Earth.
Anyway, once you've lost sight of the Earth, navigation continues, you make Clarity rolls and hope eventually you succeed and show up at your destination. Finding a gateway home then follows the rules on 218 for Leaving the Hedge, which requires a Clarity roll to get to the destination (if that wasn't your destination all along) and then do the searching Intelligence + Investigation + Wyrd roll.
Of course I might be wrong about something, or you can change things to suit you if you like.
Personally I think Cleverest is a bit wrong. For instance, Paths aren't stable at all, they're constantly changing, and there's no concept of a 'journey' as a set experience to reach a place. That sounds more like something out of Exalted: the Fair Folk. In Changeling, I'd say it's more about Will and Wyrd forcing the Hedge into a shape that suits you. Expecting a path or even a trod to be similar experiences over any kind of timescale is just asking for you to be lead to your doom.
