The sun is shinning on my keyboard, and I can see all the keys I use and the ones I don't use because of the visible dust on my keys...
Those with dust on them that I don't use:
I use all the letters from A to Z
I don't use the F1 to F12 keys
I don't use the numbers on the right hand side
I use the 4 arrows, up down left and right
I use the delete key and screenshot key and capital letters, and Alt, and Windows key and Ctrl, and escape, backspace and period and comma.
The rest are full of dust...