I always knew it, but tried to ignore it.
Always fooling myself.
Deluding into thinking any other reason.

But no.

I always knew my Gardevoir only loved the skeleton inside of me.

I mean look at that piece of calcium! How can I compete with that!?

Disgusting. Pokemon standards are always too high.

Translation of the title from your friendly neighborhood weeb:
"That it is together with humans is, to them, a celebration of life."

TL note: the Japanese is quite vague (it is written somewhat poetically with no pronouns), so I tried expressing that with my translation. FWIW, I interpret it to mean something like "Since the skeleton was with the human, for pokemon it is a celebration of that human's life."

Beautiful, but also sad ;~;.