That's good advice for certain life situations. Not really for knitting. In knitting when you're done, you're done. That last stitch is the definitive end with the exception of tying in the ends and blocking, but technically, the last stitch is the official end of the knitting project.
Not so with painting. You could fiddle forever to the point of no return. Watercolor is scary that way. One color too many and you end up with a muddy mess. A couple of strokes over the top...same thing. So different working with a thin transparent medium vs the cushy texture of knitting.
Here's my latest project from watercolor class:
Yes, that's an "apped" frame, conveniently placed. This was from a photo I took in Vermont and its official name is the Coburn Bridge.
The best part of the class was my guest, my "grand"niece, who was visiting from Seattle, where she is participating in a yearlong placement doing trail maintenance. That girl works hard! We looked up our familial relationships on this kinship chart. Very helpful. We are her great aunt and uncle and she's a first cousin once removed to my children, including my son who is the same age. The last time we were together, she was 19 months old.