what do mean by staying on the home row for everything?
The "home row", of course, is the row that starts with A. In touch-typing, the fingers of one's left hand are on ASDF, and the fingers of one's right hand are on JKL;.
Obviously, to type a 3, or an E, or a C, one's finger had to leave the home row. But because it didn't have to move too far, your little finger could stay on the A key, so that finger could easily find its way back to the D without looking at the keyboard.
Using keys in distant parts of the keyboard, like the cursor keys, the function keys, Page Up, and so on, means you have to actually lift your whole hand up off the keyboard, so you have to look at the keyboard to put your hand back in the regular typing position. Avoiding this is what "staying on the home row" as a virtue of the HHKB means.
Incidentally, in another thread, I proposed a design which eventually evolved into this:
as a more usable keyboard which attempted to retain this virtue of the HHKB - but which went beyond the HHKB Lite in adding, not just cursor keys, but most of the other extra keys, to the layout as one row of keys at the top. Others on that thread suggested more conventional laptop-like keyboards which did not require a special shift for any keys as preferable.
