I think the difference is that as a kid music is forced on you from all kinds of sources: parents, friends, radio, etc. So you don’t realize how much time you actually spent just listening to new music.
As an Old, you probably don’t have nearly as much random exposure, i.e. you control when you listen to music now. Which means the answer to your question is that you have to consciously set aside time simply to listen to music. It may feel like a “waste of time” for each track you think is shit, but that’s just part of the process.