Percentages

[Skies]

Or when you're crafting an item and you're at 96% HQ rate, then you think "Alright let's finish the item, with a 96% chance it will surely give me HQ" and it gives you a NQ item.

Makes me want to punch something.

And then right after you fail all of your touch skills, finish off by the skin of your teeth with 5% HQ chance and get an HQ item.
Yep the entire sequence happened to a friend of mine (fail at 96, succeed at 5 right after)