Yeah, I saw this coming a long time ago. They have never really been a good match as far as ambition and life plans are concerned. There are actually two conflicts that are coming up here. The first, which everyone has caught on to, is that Claire is ambitious about what she wants to do for a career, and she doesn't understand that Marten isn't. The second conflict is that Claire believes higher education is essential to pursuing career goals, because it was for her. I think, in Marten's case, even if he were to pursue becoming a repairman of musical instruments, he would balk at going to school for it.
I had a similar conflict with an ex years ago, and I think it was a part of why we broke up. She had a master's degree. I had only a 2-year degree. She used to tell me that I "have to" go back to college, it was not acceptable for me not to have a better degree.