Finally getting the hang of waltz

It's bad enough that I am severely rhythm-challenged, but when you combine that with an inability to tell left from right, it makes learning to dance (my new pursuit of late)/follow rather difficult.

To top this off, I've always had an added mental block with waltz, b/c waltzes are in 3, and yet, when I first learned it, I was taught that the footwork is essentially a box. My question--or point of confusion--always was, how does one fit a 4-sided box into 3 beats?

I have taken a few cross step waltz classes before, so I think I can now follow cross step reasonably well, so long as the lead adheres to mostly standard routines.

However, since I have never taken an intro class to "standard" (rotary) waltz, I often have trouble following a basic waltz, especially if over the course of a night, the two dance pieces are played one after another.

I am taking viennese waltz classes, and the instructor went over the basic waltz. However, instead of describing it in 3-count, he described it in 6 count, and then proceeded to give us several analogies of how to think of the steps as a whole.

Finally, finally, I think the light bulb in my head went on.

The 6-count explanation made so much sense.

Why hadn't someone explained it to me this way earlier?