It seems only yesterday I used to believe, There was nothing under my skin but light. If you cut me I would shine. But now when I fall upon the sidewalks of life, I skin my knees. I bleed. -Billy Collins
The word 'kindness', is formed by the word 'people' and 'worry'.
You worry about someone means you show concern to the person.
You understand the person's pain and sorrow.
That's why the word 'kindness' is formed this way.