It’s paradoxical, but true: you can be ‘full’ of emptiness.
This works by the same principle that can make absence more palpable than presence.
People make up the “why” of our lives. When we lose people, we lose our why:
Filling us with emptiness,
Making their absence more real than our own presence,
And explaining why we can’t say ‘why’ all this is so.
Just, that it is so.