It's not always some grand gesture of the universe that sends you shrinking, trying to understand why you can all of a sudden feel the backs of your own eye sockets. In my experience the culprit is usually without question something minute, that any other day would have been shrugged off and left forgotten, but for some reason , on this particular day, the vulnerability is there to allow that one tiny thing to tunnel its way into your synapses, tugging at the wires until it has successfully made its self the only thing you can focus on.
Before long it releases its hold on your core just enough to give all the other little things a chance to lower themselves down upon your chest as well. All the little things that formed that opening, that vulnerability, in the first place. A thousand tiny, tiny things.