From our OP’s original question:
But what of the sinner who just goes up any-old-how and receives the host (as a matter of habit, perhaps) in a state of carelessness, or worse, fully intending to mock the institution of Communion? In these cases, it can hardly be regarded as a valid communion, any more than an insincere confession is held to be valid.
I hate to judge others, but certainly, there is the appearance of this in my parish every single Sunday. Not the mocking, but the carelessness, the irreverence, the inability to recognize the Body, Blood, Soul, and Divinity of our Savior. For a new convert, and I suspect, for a devout cradle Catholic too - it’s shocking.