Thanks for the reply, PaulV. I understand the reasoning. I was considering those cases when one can place an "order" for the wrong reasons or in a bad state of mind(desire to imitate someone, jealousy etc) and realise it afterwards. Or the desired thing no longer suits your needs. Change of mind is preferable, i think, in one of those cases and I wanted to make sure we are not prisoners of our own imperfect orders
