In the second grade, we were taught that holy communion was the body and blood, soul and divinity of Jesus Christ, under the appearances of bread and wine. It wasn’t hard to understand. We knew what appearances were: it’s what we can see, touch, feel, and taste. But the substance is changed. We never used unconsecrated hosts to practice for communion, and everybody did just fine.
Of course, we received under one species only, and we received on the tongue, kneeling at the altar rail. I think if we had been given “practice” hosts, it would have been harder to keep this distinction in mind, the distinction between appearance and substance. And perhaps easier to treat the consecrated host a little too familiarly. Looking back, I’m just glad we did it that way.