Congratulations. So did I. We all did. (For some reason it's deemed quite important to teach all American kids about Marxist terms and assumptions.)
And that's where these terms belong: in history. They have little relevance for our society, today, not much more than does the term "centurion" or "vassal".
Sure, I was taught that "proletarian" meant "working class" while "bourgeois" meant "middle class". I never fully understood this though. The problem is that in America, generally speaking, our "middle class" works, and our working class enjoys a "middle class" lifestyle. So it just doesn't compute. I tried to understand those terms, and I tried to read Marx and all, but something just didn't compute.
But it still goes on: teacher writes "proletarian = working class, bourgeois = middle class" on the chalkboard and 95% of the kids nod their heads so that they seem smart. Lesson learned. Well, what can I say, I wasn't one of them. That's because I actually tried to think about what these definitions meant, and I realized that they were nonsense in our society. Grouping hordes of people into large, vaguely-defined, stereotypical categories so as to perform simplistic analyses on them while ignoring individuals is really more of a 19th century kinda thing anyway. I was never comfortable with the whole exercise myself.
My history teacher was a dyed-in-the-wool communist, he very much respected Russia and especially China. He was always telling us what good they had done for the people.
Back then I was a quiet little 16 yr old and I knew he was bonkers but I never said anything. I think that class is what made me a conservative because I could see how wrong he was.