Nihil inimicius quam sibi ipse

A man carrying a very valuable vase was walking along a street one day when he tripped and fell. The vase slipped from his hands, smashing into a thousand pieces on the ground.

The man got up, dusted himself off, and, without looking back, calmly continued on his journey.

Some onlookers rushed to him and inquired why didn't he even bother to stop to examine the pieces.

His reply: "What has happened has happened. Even if I can glue the pieces together again, it won't be the same vase."

And he walked calmly on.