They're both right. In fact, I think the second one sounds more natural.

They are both right. Don't listen to that other person. 

The first one is more grammatically correct, but you will hear both in spoken language, especially colloquially. What you really need in this scenario (someone correct me if they have the actual terminology down because i might be wrong) is an imperfect tense, but English doesn't quite have an imperfect tense (or a subjunctive), so you will see both forms in colloquial English.

Correct is 

Until met Donna, i didn't knew what friendship is