I read the sentence below:
... Which didn’t but only because I didn’t know what it was
I guess it means I had no feelings about it because ... But I am not sure. Could you please tell me what the meaning of "I didn’t but only" is?
The fuller text is:
Charles had designed my course schedule. He’d signed me up for two music classes and a course on religion, all of which he said would be easy for me. Then he’d enrolled me in two more challenging courses—college algebra, which terrified me, and biology, which didn’t but only because I didn’t know what it was.