You're looking for the theory of linear (or nonlinear) dynamical systems. Unfortunately it's not one kernel of intuition backed by consistent notation, it's many with no consistency. A good course on controls and signals/systems will beat those intuitions into you and you learn the math/parlance without getting attached to any one notational convention.
The real intuition is "everything is a filter." Everything else is about analysis and synthesis of that idea.
The real intuition is "everything is a filter." Everything else is about analysis and synthesis of that idea.