Several other things are ending as well, but let's just say they are summed by that one entity known as Finality. All things created will have an end, from which their purpose would be born.
Unfortunately, finality is a difficult concept to grasp. It is too big for a human brain; and it is too painful for a human heart. One understands the pain of transition, cherishes the value of what came to pass, and, ultimately, laments the transience of memories. We know this to be true, but it seems to be always outside our control.
We cannot stop change. We have no choice but to embrace it.
And I have to say goodbye. 'Til we meet again.