Making Your Own Sword
Imagine a system as a mine. Within this mine is ore. You can dig it up.
Imagine your game as a furnace. You can smelt your ore here, and end up with metal.
Imagine the page as an anvil. You can hammer yourself a sword from all the metal you’ve found. The sword will change over time. You’ll have it with you, wherever you go. With a good enough sword, you don’t need to go to the mines.
I could give you this sword, and you could use it - but it might not fit your hand. I made it for me, after all.
Imagine a book as a burial. I return my sword to the soil, where it will oxidise and return to ore. You might dig up that ore.
A mine without ore is a hole in the ground. The value of a mine is where it is, not the hole itself.