How did you like the last book you read? What did you learn from it? The time period over which a book, movie or regular conversation releases its impact on us can vary radically. Some books we read and we know immediately that the challenge us on several levels. Others work their magic over time, sometimes in secret away from our conscious awareness.
With the Happiness Project by Gretchen Rubin I thought initially it was an easy and enjoyable if slightly superficial read. Until I picked it up again two years later and saw that lots of her ideas had suddenly become my ideas and that her key idea, experimentation was suddenly much more part of my life. Some conversations or movies change our lives right in the moment and we know it immediately. Others are more subtle and almost humble because we might never be able to credit where the impact came from.