Do I have "the right" as a grad student to take a class just for fun? I'm currently doing a PhD in computational biology, but I have other interests like music and ceramics, and I'm lucky enough to be at a university with excellent programs in both. I've wanted to take a course in either of these fields for the 3 semesters so far I've been here, but my advisor won't approve and sign off on them. I have a free slot this spring and I really want to take a course just for fun, and to learn from the world-renowned instructors. I've tried negotiating about just taking an evening class, or having my work for him improve since I'll be happier overall, but he's just stuck on "this isn't your field". Who's being unreasonable here?
Just turn up for the class. Don't register; just sit-in. Afterwards, explain to the instructor that you're studying a PhD in computational biology and that you have a personal interest in the course. You won't get credit, but you're fulfilling a personal interest, not an academic requirement.