if you truly love someone then you care about their happiness, and that includes caring about their interests. you should naturally want to support their interests because you want to make them happy.
the point is: don't just pretend to be interested. but try to honestly care. if you honestly love this person, you should be able to. pretending may help to get you started, but if you have to keep pretending, you may end up unhappy. better find something else to love about your partner.