Sometimes I'll hear some music in my head or I'll go to the piano and mess around and come up with a tune, or be on the guitar and come up with some chords - or I'll come up with lines, or just some words, or just a sentence. It could be the title of a song. I do that all the time. I write titles of songs a lot. And sometimes I'll end up writing a song that I don't have a title for and I'll say, "Oh, this goes with that title".