After I posted the blurb about meta tags, I went upstairs and took a shower, and since I always do my best thinking in the shower, I realized that the two sets of robot tags aren't necessary together, i.e., if you don't want the robot to index your page, then it obviously won't cache it since it didn't index it.

So if you use the "noindex, nofollow" tag, then the "nocache, noarchive" is redundant. You might, however, want to have your page indexed, but not cached, in which case you would only use the "nocache, noarchive" set. I'm not a very good teacher and don't always explain things well, so if this is confusing and anyone wants to discuss it further, please don't hesitate to write.