Insidious

It always amazes me that people who consider themselves really good, kind people can be so unthinking and cruel.

I suppose that is better than being knowingly cruel.

Unless you are the victim of their actions.

In a way this makes them more insidious than ever as they go around inflicting others with their short sighted form of kindness and tom foolery.

Trying to open the eyes of someone who sees himself, or herself, as the picture of sweetness is like pouring water through a sieve.  Pointless.