I find them by playlists and recommendations. I was just as picky in music 5 years ago, but still discovered songs that would completely wow me at first listen. Whether I'm picky or not doesn't answer whether it's common that people stop having a strong response to new music after a certain age. If I'd ask my parents to list there top 10 songs, i don't think it will contain anything after their 30th. Maybe 1 exception .

You say reddit can't answer the question but everyone else just gives me a normal answer.