A Macroscopic Analogy

One way to think about energy barriers between molecular states is to compare them to transitions in macroscopic objects
One of my favorite macroscopic objects is a canning jar that holds my coffee
The jar has a spring clamp mechanism that holds the lid tightly down over the top of the jar, in a stable 'closed' state
When the lever of the spring clamp is pushed out, the mechanism briefly enters a 'strained', high-energy transition state before acquiring a loose 'open' state
In a similar way, the bonds and electronic interactions between atoms in a molecule define 'strained' transition states between stable molecular configurations