The book "Beautiful Oops" was a BIG help with this issue for us. Also, we talked a lot about inventors who didn't get it right the first time, artists who weren't famous in their lifetime (but look how beautiful their work is now)-that sort of thing. It was a conversation we had many many times over a few years. Also, my daughter loved the Eric Carle book "The Very Hungry Caterpillar" and we went to his museum in Massachusetts where we learned that book was originally about Willie the Worm, but he changed it to the caterpillar. So we've basically had an ongoing conversation about lots of people who weren't "perfect" but look at the awesome things they've created/painted/written/invented by keeping on trying.