A freely falling body drops slowly at first, then gains more speed over time. Its curve is exponential.
The C and L curves drop quickly at first, then become shallower over time. They are linear devices (as far as the ideal sense).
Consider a diode. As voltage increases linearly, current goes up exponentially. It might better describe a falling body.
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Or a battery as it discharges into a load. Volt level falls slowly at first, then quickly as it gets completely discharged.