Universally misplaced cursor keys:

I learned in the early 1980’s that actual experiments had determined an ideal layout for cursor keys, and boy does this make sense: three keys in a line, with the fourth key placed BELOW (not above, as is nearly universal) the other three. That lower key is handy for your thumb, and if you try it, you'll find your fingers are more relaxed than in the up-arrow-above-the-others layout. Just try to buy a keyboard built that way.