Don't try to like the things you think you ought to like, just let yourself like the things you do like.
It seems simple enough, but I found it quite difficult to actually do. If you succeed though, it not only makes you happier, it also seems to inoculate you against pretentiousness.
I don't know. It took me a lot of time to gain any kind of appreciation for classic literature; I would often at least publicly claim that it was all a nexus of empty pretension. But I kept at it, motivated mostly by guilt, and I've developed an appreciation that means I can enjoy things that more people can talk about (compared to the sci-fi I've always read), and that makes me feel better about myself. Whether I'm actually better off is of course an open question.
Editing your own reward matrix should certainly be approached with extreme caution, but I see no reason to rule it out altogether.
Don't try to like the things you think you ought to like, just let yourself like the things you do like.
It seems simple enough, but I found it quite difficult to actually do. If you succeed though, it not only makes you happier, it also seems to inoculate you against pretentiousness.