Lyric discussion by LexGabinia 

Cover art for Dear Mr. Fantasy lyrics by Traffic

One evening, Capaldi was doodling in the battered old notebook he kept for potential song lyrics and ideas. "I drew a little character I called Mr Fantasy and next to him, I started to write, Dear Mr Fantasy . . . It was a letter to my cartoon character." Retiring to bed, Capaldi woke later to hear Winwood and Wood playing in the music room. When Capaldi came downstairs he discovered that they had found his drawing and put a melody to his letter.

http://www.stevewinwood.com/news/5765

@LexGabinia It looks like that link got moved to:

https://stevewinwood.com/news/1424

@LexGabinia What a great little story about how the song got created. Thank you for sharing that.