Sometimes, you just gotta learn the hard way.
My never again experience was agreeing to "fix" a quilt for a friend. It was a t-shirt flimsy that needed to be a quilt!! And, it was definitely not square blocks. More...willy-nilly. Ugh! By then, I didn't want to say forget it, so I did the best I could.
Now, I have no problem with the word: No.