dear dr john -
have seen/heard ? the quote before, so maybe i can SEARCH it back to its source for you all. seems it was in/from HIS bio. so that is where i will start.
PS: and my quote for this Post ...
"All my life I have felt myself to be on the edge of things. All my life I have suffered from bad dreams. All my life I have had difficulty in knowing whether I am awake or in a nightmare."
Tom Baker - from his auto-biography
2PS: BINGO! Found it! Your quote WAS from the bio, dr john.