Know or listen to those who know.
If you can dream it, you can do it.
After a storm comes a calm.
Problems are not stop signs, they are guidelines.
If you've got a talent, protect it.
Be kind whenever possible. It is always possible.
The wise does at once what the fool does at last.
Who seeks shall find.
Expect problems and eat them for breakfast.
I can, therefore I am.
There's obviously nothing wrong with selling your art - only an idiot with a trust fund would tell you otherwise. But it's confusing to know how far you should take it.