Does "I came across" make reference to the past?
You are correct that "I came across" is a reference to the past. In fact, "came across" the past tense of the transitive phrasal verb "come across", which means to meet someone, or to find something by chance. You can think of it as a kind of synonym to "discovered" or "found". Ex: I came across a word I’d never seen before. Ex: Have you ever come across such a horrible person in all your life?