sometimes its depression numbing yourself so you don't feel sad or angry or anything so you don't hurt inside and out
sometimes its tiredness thinking and feeling and empathising so much that your emotions shut down you smile nicely at everything and you know how to react just enough to look okay
sometimes its wishfulness hoping and praying so hard that the pain suffered by the one you love could disappear, because you're helpless and you want so badly for them to feel better
because emptiness is what they feel so maybe somehow by feeling the same way it'll help them it's worth a shot