When will I know?

I hadn't intended to publish a post this evening but when I moderated a comment and had to come here anyway I thought...why not? It's a question I've never been able to answer for myself so perhaps someone else will know. It was written by me many years ago and has become just a tattered piece of paper that hung in my studio for years, and years. Taunting me with its profundity and yet enigmatic presence. So I ask my readers to answer this question:
When will I know I have enough, and what will I do then?