I love that Adam Savage always shows his projects from beginning to end and that he’s happy to show that working from the concept through to the final design isn’t always a smooth process. There will be issues. Measurements will be wrong. The concept may not work as envisioned. It takes longer than expected. Corrective action may be needed just as it seems like the project is finished. In other words: this is normal. Whether you’re building software, composing music, painting or working on a book, you’re going to run into problems. This doesn’t mean you’re a terrible creative and you should stop. It’s part of the process, so don’t sweat it. Just get up early in the morning after inspiration strikes, make your adjustments, and finish.