What we know

You think you have tested everything, and you still feel insecure and don’t want to go to production, because you don’t know what other bugs are still in the system, what situations you didn’t cover.

You want more time, to make sure everything will go well, but even so you will never know everything, because there will be mistakes you don’t yet know you have made, and there is no way to find out until you have shipped your software to production so users and your customers can try it.

Curiously, Donald Rumsfeld (yes, that one) put it lyrically:

As we know, There are known knowns.
There are things we know we know.
We also know
There are known unknowns.
That is to say
We know there are some things
We do not know.
But there are also unknown unknowns,
The ones we don't know
We don't know.

– Donald Rumsfeld

Every developer is a perfectionist, but the perfect is the enemy of the good. Yes, version 1 sucks, but ship it anyway!

Worse is better, hard as it is for us to accept.