After my second-to-last record 'The Greatest' I had gone on tour for a while and I didn't play an instrument for about five years. And I got kind of - it's not self-esteem or whatever or anger toward myself - but disappointed in myself that I hadn't been challenging myself to learn musically.
Our understanding of the world around us is constantly being redefined and expanded and so therefore it is wiser to be passionate about seeking for truth than knowing it.