Sometimes you have to just 'do life', just get up and make the best of right now, rather than waiting for everything to be perfect, because that day might never come. If you spend your whole life wishing for something or wishing something hadn't happened, you'll waste it.
For a parent bereaved of a child, the loss is always present, even years and decades afterward. It never goes away, but you learn to live with the pain.
Grief is the price we pay for love. It is loving and being prepared to risk the pain of losing that love that makes life worth living, in the end.
Kate Lynn-Devere wrote these lyrics about the death of her daughter Alex. Alex died very suddenly, of a previously undiagnosed heart condition. The book of shadows is grief - people say that when a child dies, the shadow of their death is as long as their life would have been. The shattered promise is all the stuff Alex might have done, if she'd lived. The sudden death of a child is devastating and very hard to understand and cope with for any parent.