These are John Tenniel's pictures of Alice, who knew what it was like.
Ruthful means causing sorrow, which no sane person would wish to do. It also means feeling sorrow, which similarly no one sane would wish to do - unless they're feeling particularly self-obsessed or self-dramatising, which I must admit is rather a lot of people rather a lot of the time.
Ah well. I suppose it keeps the book and film market afloat.
Ruthful means feeling pity, too, which is an important and necessary thing; but then it also means causing pity, which is something greatly resented by some people and greatly courted by others.
Complicated, aren't we?
Thing To Do And Not To Do Simultaneously Today: be ruthful. Whichever way you do it, cause no harm. This word arrived in English in the 1100s from rewen which means to rue, from the Old English hrēowan.