All endings are also beginnings. We just don't know it at the time.
What makes this observation so quietly subversive is that it refuses the comfort of closure—it insists we can never actually experience an ending, only its mistaken identity. When you lose a job or end a relationship, you feel the loss completely, and that feeling isn't somehow negated by what comes next; rather, Albom is saying the present moment obscures what's already germinating beneath the surface. A woman who left medicine to become a novelist didn't experience her final day in the clinic as the beginning of her real work, only as defeat—yet that's exactly what it was. The quote's mercy lies not in happy-ending thinking, but in the radical uncertainty it preserves: you cannot know what any loss will become.