This sums it up. That cool song you would like to know the name or artist? Bad luck if it wasn't popular. Where does x idiom come from? Wait until you're at home/the library.
You would have many of these unresolved questions for years, until some solved itself fortuitously.
I had a particular set of notes stuck in my head for decades. Then one day about 10 years ago I finally managed to remember one of the words of the song, and with that actually managed to google the song. I thought it was something I would never hear again. That song is My Love is Alive by Gary Wright. I remembered the 6 notes in the bass line and that had been driving me nuts for decades.