The most powerful sign is that your work no longer enchants you - it's not deep, delightful, and mutually satisfying. When this happens, it may be time to look for new challenges.
Guy KawasakiLooking back on my own career, I've come to the conclusion that too much money is worse than too little.
Guy KawasakiWriting a book is as different from digital curation as night and day. Digital curation is a series of split-second decisions: good/no good. It can even be done algorithmically. Writing is process-intensive activity.
Guy Kawasaki