It’s probably that with age you have developed the patience needed to appreciate the classical works. Typical ‘pop’ tunes only last around three minutes, and listeners become accustomed to that pace, so when they’re faced with classical works that may take far longer than that just to get through the introduction, they just don’t have the attention span to appreciate the more expansive themes.

Classical works also tend to deal with more complex and nuanced emotions, that involve different areas of the brain. The aim of classical works is often totally different from popular music, although there is a place for both. To paraphrase Leonard Bernstein, pop music is in the entertainment business, whereas classical music is in the beauty business. While that is an oversimplification, it’s more or less accurate.

One thing is fairly certain though — it’s probably not just a phase. Once you’ve found the pleasure of classical works, it’s unlikely you’ll ever lose that appreciation. What you may find however, is that your taste may continue to develop, to include other genres and new composers. For example, it’s often noted that Brahms’ music in particular, may not appeal readily to the young but is typically appreciated more deeply later in life.