My old drafting instructor told me to never trust a measurement twice. I thought he was just being dramatic.
Back in trade school about 8 years ago, Mr. Henson used to yell at us if we measured something, looked at it, and then measured the same line again without writing it down. I always figured he was just old school and cranky. Then last month I was working on a set of floor plans for a small office remodel in Austin. I measured a wall at 12 feet 3 inches, got distracted by my phone, and measured it again a few minutes later. This time I got 12 feet 7 inches because I had the tape at a slight angle. If I had just trusted that first number and moved on, I would have ordered the wrong stud layout and cost the client an extra day of labor. Now I write every single measurement down the second I call it out, no exceptions. Has anyone else had a bad experience from repeating a measurement that messed up a job?