Lily went to India countless times. During one such trip, which was dedicated entirely to yoga, she visited many yogis with the intent to write a book about them. Her journey led her through much of India and to sacred Hindu sites where yogis tended to gather. In Rishikesh, a sacred village in the Himalayas that was a major centre for yoga, she received instruction in Vedanta philosophy. Lily’s exposure to Indian philosophy had an enduring and decisive influence on her. Her book Een jaar bij de yogi’s van India en Tibet (A Year with the Yogis in India and Tibet), written as a dialogue, presents a number of difficult, abstract religious concepts in a comprehensible way.