yes you must! ^-^
I think I posted it in here before but I feel like chalk refers to how easily life is taken away. Chalk's quite a soft rock that crumbles easily and I think that refers to how life is quite a fleeting thing. We're not these big, strong, indestructible mammals as we'd like to believe, we're easily destroyed beings. I feel like the different parts of the song are for stages of dying, struggling and fighting it at first and then accepting death.
Still sounds like dolphins having sex kind of. Nahh your interpretation makes sense! It's marrow i think inside your bones?