Nothing prepares you for your parent getting ill. No explanation about how entirely the proper order of your world is capsized conveys sufficiently the enormity of it.
Shared memories of a lifetime become secrets. You hold your parent's hand in your own. Their's lacks the authority it once had. The command. The strength that provided you assurance that all would be well. And when you hold their hand, you are simply be as grateful as anyone has ever been about anything before that you have this moment.