An epistle is a letter, and this song takes the form of Donovan
writing to a friend - a technique he later used on his song "To Susan On The West Coast Waiting
." He talked about this song at a 2004 appearance to promote his album Beat Café
: "Dippy was a school pal. He had signed up in the army, so I wrote a song that I hoped he would hear on the radio and call me. It related to school and what I was going through and had references that he got and he called me - and I bought him out of the army, which you could do. So it was a creative use of radio."