Nothing is a waste of time if you use the experience wisely. ~Auguste Rodin
I’ve had so many experiences in my life that others might see as failures but I decided to see as an opportunity to learn something new. Sometimes you have to try something, make a small adjustment and try again. You can always build on what you’ve done before. That’s what using the experience wisely means to me.
Another way to look at it is practice and as an artist we should always be practicing. That really is the best way to improve.