Sliced bread is so great because it's hard to make a sandwich out of an unsliced loaf of bread. I suppose you could just use a roll, but that's not the point, is it?

Is it sliced bread if you have to slice it yourself? Well, if you make your own bread, you probably slice it yourself. If you've tried this, then you really know why sliced bread is so great! It's difficult to slice it by hand and get the slices even, even with practice. And uneven slices don't toast very well, unless you like one side more burned or less toasted than the other.

So, I'd say, what makes sliced bread so great is 1) a machine did it instead of you, and 2) it's an even, uniform thickness slice.

Then again, maybe I'm just lazy and don't like to slice my bread. Some day, perhaps I'll buy myself a bread slicing machine.


Update: My exuberant thanks to simonc who has confirmed and fully explained my suspicions!! I'd like to add that sliced bread not only goes stale faster (which wrapping helps), but also goes bad faster, which wrapping does not help. Innovations (and their problems) will never cease!

I'd also like to thank lj for his excellent manual slicing advise, all of which I've always followed; however, one important thing is left out. You can follow all of those tips, and none will help you make a nice slice of bread nearly as much as many repetitions of practice. Just knowing how to do it is not good enough to get those nice even slices -- it's just not easy!