I also like some opera...and lots of other music also... and that is the only criterion (for me) do I like it!!! for opera a knowlede of the story , from a synopsis if not a full libretto usually helps in the enjoyment but there is a particular opera "Lucia de Lammermuir" by Donizetti which i dont know the story of, andI enjoy enormously because the music is sublime.. A tip, that Has often been said, sometimes the voice is used in song to communicate the words, but sometimes just as another instrument.. I believe this is true, as in "Lucia" I think ,for me, knowledge of what the words "mean" would in fact detract from the "musical experience"
A little story, a group of us went to the English National Opera ro see Mozarts " The Magic Flute" one of the group pressured her boyfriend, a Rock drummer, who had NEVER heard ANY live classical music into coming with us. As we were leaving the theatre at the end of the night, we are descending a long staircase from the gallery with about 200 other people when the b/f said, loudly, " Hey this guy Mozart wrote some real nice tunes" there was a lot of laughing and applause from the other patrons!!! but the point is he had an incentive to listen and found that he enjoyed it. That That the Music is sublime and it was in English probably helped.