What song were you humming on Bayshore Boulevard?

You were skating along Bayshore Boulevard at 6.30am on a pair of old roller skates, so slowly that a cyclist overtook you twice, and you were smiling like it was the best idea you had ever had. I was running past with headphones in. I took them out to hear what you were humming. It was a very old song. I did not catch the name. I ran the boulevard the next day without the headphones. I heard nothing. I heard a great deal of nothing.