I was told that the perfect tense is for when you are saying stuff like "I drove" or "I ran." The imperfect, on the other hand, is about saying stuff like "I was running" or "I was walking." Are you all saying that this distinction I was taught is incorrect and the the perfect is not,in fact, about saying something that definitively happened in the past?
No, what you've been told is right.
The Latin perfect tense does mostly refer to the past. Originally it was actually a merger of two aspects, the aorist and perfect. The aorist simply refers to the past, and is a one-off thing. The perfect referred to what happened in the past but still has continuing relevance in the present. Most of the time in Latin it is the aorist part that shows through, but the old perfect sense still exists.
Most obvious is with verbs like odi and memini. They're actually perfect in form. In fact, only
perfect forms exist for them, but they have a present meaning. Not 'I hated' or 'I remembered', but 'I hate' and 'I remember'. But every verb can act like this. feci can mean I have made (perfect) and I made (aorist, straightforward past tense).
1) cur non possum videre pecora? Why can't I see the flocks?
iam egi pecora in valle. I've already driven the flocks into the valley.
2) quo pecora egisti? Where did you drive the flocks?
egi pecora in valle. I drove the flocks into the valley.
Number 2 shows only the aorist aspect of the perfect tense, it doesn't say anything at all about the present state of the flocks. The shepherd's just saying what he did in the past. But if someone was asking him where the the cattle were now or why he couldn't see them at this present moment, the shepherd would answer with the perfect aspect of the perfect tense. That would be number 1. Same verb, different context.