My grad school wouldn't accept my undergraduate German language credit, so I had to take German again in grad school.
Easy peezy, right? nope. The teacher walked into the room talking in German and she wouldn't stop to translate. Instantly I was treading water there and had to work desperately hard to keep up in that class or else I'd not get my graduate degree.
We were living in college married housing and I told my husband (also a student) that for that semester, I wasn't doing any housework or cooking. It would be Study German All The Time for me. (yes, I passed. Whew!)
(Some years ago I had met my husband-to be in German class. He was great in languages, so his German credit was accepted by the grad school.)