One of Micky Dolenz's competitors for his role in "Circus Boy" was singer-songwriter Paul Williams. Ten years later, Williams competed with Dolenz again, for a role in The Monkees (1965). Williams didn't resent Dolenz for beating him out twice, and the Monkees later recorded one of his songs, "Someday Man".
Star Micky Dolenz's hair was dyed blond for his role; he grew the dye out after the series ended. Years later when a reporter asked him why his hair looked different, Dolenz joked "I guess you could say I'm a Hollywood phony from way back."
During the show's run, the producers decided to send Micky Dolenz on a promotional tour (together with the show's baby elephant), and that an added attraction would be to have him play guitar and sing. Dolenz was sent for a round of guitar lessons, and alternated between music and tricks with the elephant for the tour.