Lesson learned--now, why do you have a machete?

Today my oldest munchkin learned a good life lesson. He worked long and hard to do something he'd never tried before and it didn't work out.
He was making a denim sheath for his new machete. I had to walk him through basic sewing over the phone, because patience until I got home from work didn't seem to be an option. After the cutting and the hand sewing he realized that he had measured wrong. The fat part of the machete on top has to be able to slide through the whole sheath, so a sheath measured as an exact mirror of the machete will not work. Thankfully I was home by the time this was realized, so the frustration of finding more material and starting from scratch was diminished a bit.
I work hard to try to teach my boys what they need to know in life, but some lessons come without me even trying. I hope he gets it right this time.