“Mistakes build character.” My mother told me that a lot.

My Uncle Ralph, who taught me woodworking and helped me build my kitchen cabinets, always knew the mistakes I’d make before I made them.

“Damn! I just routed off the wrong side of the rail!” I’d shout. And he’d startle me, saying up close: “Of course you did.” Then he would hand me a new piece of wood to do it again (correctly). It was infuriating.

“I knew because I’ve done that mistake a hundred times,” he’d say.

My brother Paul did his medical internship where I was in residency. We still both remember a particular patient who was dying. Delirious, headache, fever, stiff neck, septic shock. Paul set up the lumbar puncture tray and demonstrated perfect technique on a difficult procedure. He lifted up the first tube, which contained crystal clear cerebrospinal fluid. “Dude! Nice!” I shouted. I was proud as hell. The whole stepdown unit was looking at him. Then, using the same hand that held the open tube, he reached for the tube’s cap — turning his wrist — and he accidentally poured the valuable CSF fluid he’d worked so hard to collect onto the floor, droplets splattering in sparkling shards. “Noooooo!” we both shouted. He never, ever made that mistake again, and to this day, I always think about it when holding an open test tube.

Abby was a great med student. Her patient needed a rectal exam and a guaiac test, where the gloved finger is swabbed on a card to test for occult fecal blood. Abby had never done one but quickly volunteered. I was busy with an emergency, but she didn’t want my help.

“How difficult could it be?” she asked.

Later, she returned, ashen. “I couldn’t do it,” she said.

“Why?” I asked.

“My finger just wouldn’t go in,” she replied.

“Was here a large obstructing mass?” I asked.

“Well, I was nervous, he was nervous, so I told him to just relax, bear down,” she said. “I tried to do the exam, but my finger just could not be inserted. And it hurt the poor guy. No mass, just ... friction.”

And then it dawned on me. “Abby. Did you use Surgilube?” I asked.

She hadn’t, unsure if it would “mess up the guaiac.”

Lessons learned: 1. Always, always, always use Surgilube. 2. Don’t let someone do their first procedure without supervision.

Advanced Cardiac Life Support used to include a “precordial thump” for someone in a deadly rhythm called ventricular fibrillation. The precordial thump involves giving a closed fist punch, hard, directly in the sternum as initial therapy when better therapies aren’t yet available. (It is not thought to be a very useful procedure now.) One night on call during residency, the alarm sounded that a patient was in ventricular fibrillation. As the nurse called a “CODE” and got the defibrillator, I ran into the patient’s room, saw the guy still in bed, and thumped him, hard as I could, in the sternum. He opened his eyes immediately and shouted at me: “Hey, what did you do that for?!” Turns out he wasn’t in ventricular tachycardia, but he had scratched himself, which caused a bunch of misleading noise on the telemetry leads.

I, too, have made many of the usual mistakes. I’ve tied off the wrong vessel, opened the wrong stopcock, prescribed the wrong dose, stuck a needle too deeply. I’m ashamed of my mistakes. I’m simply too stupid to learn from some of them, but hopefully I have learned some lessons. It’s true that you never stop learning. Unfortunately, as I get older it seems the mistakes don’t become any less frequent.