history: I thought that physics was gonna be a really simple class. Contrary to this, it was really tough and was one of the hardest I was in. I really thought that physics was gonna be an easy class last semester. Physics is an interesting subject_comma_ but it can get difficult to understand sometimes.
current: Agreed, since it was way harder than I anticipated.
next: Hopefully you won't have to take an additional Physics course in the future!