I watched a presentation he gave a few years back, and he said when he initially took piano lessons as a kid, the teacher was teaching classical piano, and he wasn't liking it, so she recommended to his parents that they not waste any more time and money on it. It wasn't until his teens when he discovered jazz piano that he really got into it; when he failed at trying to get his friends interested in jazz was when he started arranging modern music in jazz styles.