Who gets to determine when the old ends and the new begins?

“Who gets to determine when the old ends and the new begins? It’s not on the calendar, it’s not a birthday, it’s not a new year. It’s an event, big or small, something that changes us. Ideally, that gives us hope, a new way of living and looking at the world, a way of letting go of old habits, old memories. What’s important is that we never stop believing we can have a new beginning, but it’s also important to remember that, amid all the crap, there are a few things worth holding on to.”

— Grey’s Anatomy