It was the early 90s, before I'd ever done a stint with a wrench in my hand. My headset had been loosening up badly ever since my hometown shop installed a new suspension fork. I hand-tightened the thing AGAIN (remember, kids, steerers had things called threads in those days) and rode it to one of the shops in the town where I was going to college.
The mechanic there correctly diagnosed that the steerer tube was cut too long. And he proposed the correct solution: Add a headset spacer to take up the slack.
But I was a perfectionist, and I absolutely could not believe that the incompetent mechanic at my hometown shop would foist such lousy work on me. I refused the headset spacer on principle and rode off with my headset clunking. Nose off, face spited.
Next time I was back home, I took the bike back to the shop where the fork was installed and pitched a minor hissy fit about the problem. The shop owner proposed the correct solution (again), a headset spacer. But I wasn't hearing it. So, to shut me up, the shop owner promised to have the steerer cut shorter.
Then, things turned uglier. That poor mechanic overdid it and took off too much steerer. The shop owner -- dreading the second hissy fit that he was sure would follow -- ordered a new steerer and made the mechanic pay for it. Now that I think about it, he may have needed to order a whole new set of uppers: steerer, crown, and stanchions. Or maybe parts weren't available for that cheap fork and he needed to order a whole new fork. Whatever it cost, that mechanic (probably making $3.85 an hour) had to eat it.
All because I refused a headset spacer.
Dude, whoever you are and wherever you are now, I am so sorry.