In 1892, in filling out the well-known questionnaire (Lindenberg does not state which questionnaire this is) Steiner answered the question “which vocation seems to you to be the best?” with the words: “Any vocation in which one’s entire energy will be used to its fullest.”
Source: Christoph Lindenberg’s Biography of Steiner – Epilogue, page 763
The great Rudolf Steiner Quotes Site 