I'm in my forties and still looking for and discovering new metal, jazz, and classical artists. You don't have to get stuck in the past listening to stuff you discovered as a teenager. But you've got to make an effort.
The closest thing I can think of to that though is the album Strawberry Jam by Animal Collective. The song Bonefish is a good representative sample. My brain couldn't process it at first... It made no sense until after a few listens and a hit of weed.
Likewise, there's this Japanese pianist named Hiromi Uehara. She's been performing and recording for at least 15 years, and has worked with artists like Chick Corea, but I hadn't heard of her until this morning. She just dropped an album called Spectrum, and it's absofuckinlutely brilliant. If I didn't make a point of looking for new music, I'd still be missing out.