Zero conditional form

Chatting with a colleague we came a cross a dilemma (as we are not English native), which of the following sentences are wrong? Why?

1. If I knew everything, I'd be a genius.
2. If I know everything, I'd be a genius.
3. if I know everything, I'm a genius.

The 2nd should be wrong, as with the present I should use either the future or the present, in fact the 3rd seems to me correct, in fact the rule is:

The Zero Conditional is used for actions that are always true when the conditions are satisfied.

So to form this particular condition I use this form:

If + Present Simple, + Present Simple

Am I wrong?

Solution 1:

Sentences 1 and 3 are both correct.

Sentence 1 is a counterfactual conditional sentence, and sentence 3 is a factual conditional sentence.

Factual:

In these constructions, the condition clause expresses a condition the truth of which is unverified.

Counterfactual:

In these constructions, the condition clause expresses a condition that is known to be false, or presented as unlikely.

Sentence 2 is indeed wrong because it is mixing the two in an incompatible way.