Ask HN: What was your most humbling learning moment?

I was rooming with a girl I barely knew for the summer and was looking out the window while washing dishes. You know how fireflies tend to sync up? Suddenly I see hundreds of tiny yellow lights turn on and then off. On and then off.

I yelled for her to come in (at least to my credit I was more fascinated than afraid!), and she ended up dumbfounded that I had never seen fireflies before!

Unfortunately, the program was difficult to test (no unit tests) and very important, and difficult to verify correctness of output as well. (As in, you can't just look at it and say "yeah that's numbers lgtm").

Also unfortunately the previous author had not been very consistent in their programming style, so there was a lot of syntactic noise (some single line if statements used braces, some omitted them, etc)

Also unfortunately in my prior rewrite work in this, I had grafted the old UI onto my new backend to save time, but not brought the rigor there up to snuff (it's UI code, I had thought. It's well enough to have tests covering the business logic for now.)

Well anyway when I had rearranged some code, I hadn't realized there had been an extremely large block right underneath an if statement that wasn't using brackets, and I had accidentally split it into a few statements. N-1 of which were naturally now outside of the if statement.

The end result being that a bunch of code would run and the "is dirty" state worked fine, but if you clicked save on a "clean" state with no edits, it would blank the fields in the DB but not in the UI.

It didn't end up having any actual impact because we caught it in time, but god damn did it teach me something about "real" programming. I'm not sure exactly what all it taught me, but I think about that a lot as I do random other things now 8 years and 3 companies later.

I apparently have trouble learning life lessons.

I "knew" this and a had a really good friend who did not. Both of us grew up in the same area, and we met in school, so you'd expect we should agree on this, right?

While "arguing" about it one day, it turns out the suburb they'd grown up in had several private subdivisions where the builders could do whatever they wanted. Houses were numbered sequentially following one direction of the private street, then the other. So the house nearest the entrance of the subdivision would be "100 Maple Street" and across the street would be "143 Maple Street".

Because they'd grown up mainly going to other friends' houses in the private subdivisions, my house address was the odd one and theirs were normal to them.