When you think about it, most things in the natural world are distinctly different, if only in subtle ways.  Mother nature, apparently, is rather weak in the quality control department, and allows all sorts of inconsistencies and variations in her handiwork. No wonder she isn't ISO 9000 certified.

OK - kidding aside, we live in a human world and in that world things are consistent, replicated, and identical.  That's not a bad thing - when I make prints, for example, I want them to look exactly the same and go through great pains to make sure that they do.  But that's not the way nature works. We recognize that and appreciate it in the very narrow category of snow crystals.  That's great, but snowflakes are the rule, not the exception. So the next time you look at a leaf, or a bug, or a bird, or a fish, or a squirrel  - think of it as a snowflake, resplendent in it's uniqueness, no two alike.