This additional explanation might take you to a maze though,
에서 has the meaning of 'in/on/at' too.
학교에서 점심을 먹었어요.
I ate lunch at school. (when I was at school)
한국에서 영어를 배웠어요.
I studied English in Korea.
As you can see, however,
에서 refers to some moments or places where the ocasion starts from.
On the other hand,
에 has the meaning of the ending point or the target place.
julialim wrote:manyakumi님 You are such a good teacher.