What I do not know, I do not think I know.

The more you know, the more you know you don't know.

You don’t know anything, but I know even less.

« You only think you know, as a matter of fact. And most of your actions are based on incomplete knowledge and you really don’t know what it is all about, or what the purpose of the world is, or know a great deal of other things. It is possible to live and not know.

You don't know that for certain

if you think you know what is going on, you haven’t got a clue about what’s going on.

Of course you don't know. Nobody knows why; we only know it's so, and can't tell why it's so.

Je sais que je ne sais pas ce que je ne sais pas.

A man doesn't know what he knows until he knows what he doesn't know.

you don’t know what to expect. No one does. Not really — not in real life.

It is more important to know that you don't know, than to know what you know.

The unknown words remind me that there's a lot I don't know in this world.

So, on beyond Z! It's high time you were shown That you really don't know All there is to be known.

You'll never know everything about anything, especially something you love.