Almost ruined a custom knife by skipping normalization...
I was forging a blade last week and got in a hurry... so I didn't let the steel normalize after heating. Right after quenching, I spotted hairline cracks along the edge. That weak spot meant the knife could have broken during use. I had to reheat the whole piece and cool it slowly... which took extra hours. Now I make sure to normalize every time, even on simple projects. It's a small step that keeps the metal strong and safe.