Funny language story. I was reviewing someone's code a few weeks ago, in VB6.
VB still supports a bunch of the old anachronistic BASIC language features, like line numbers.
I noticed an arbitrary "4:" on one of the lines and I asked him why it was there.
He replied, "I don't know, but it doesn't seem to hurt anything".
I literally facepalmed.
I have a really weird one.
Many years ago (mid-1970's) I was working for an engineering firm in Chicago doing some heat transfer calcs. They had access to a computer somewhere and I would dial in on an acoustic coupler modem. I thought that my code was correct (in some bastard language called "super" fortran), but it kept crashing. I put in all kinds of diagnostics (print out values of this and that, etc.) and when I did the code ran perfectly. I took them all out and it crashed.
Then I started taking out the diagnostic lines of code one by one. I could take them all out but one. If I took that line out the program crashed, but if I left it in the code ran just fine. It was a real head scratcher. Finally I replaced that line with a CONTINUE statement. And the code ran perfectly.
To this day have don't know for sure what was going on. But I was never fully confident of anything that came out of that computer after that.