You know how metroidvanias gate progression by having, for example, a jump you can't make without an upgrade, or a poison area you can't survive passing through without a way to be immune to poison, and so on? That, but instead of it being an upgrade your character gets, it's knowledge. You find a clue somewhere in the game that allows you to solve a puzzle elsewhere. You were always able to take the actions needed to solve it, you just had to learn that you could.