Let's get one of those fun discussions going again. So during my commute, the radio station I listen to has a segment called The Fact Controller where people phone in with confessions of things they took as fact for years but were actually completely wrong.
I figured, why not do the same thing for level design. I've looked through a few of my older maps in the last couple of days, including some backups from The Core's early days and was ashamed to find some hilarious solutions to non-existent problems. Here are two of mine.
1. I was totally unaware that the locked door sound would play if a func_door was named but not triggered. My solution was for the locked door to be a normal world brush, with a 1 unit thick trigger in front of it that played the locked door sound when the player touched it... I only learned the truth in 2012 after Archie joined me in developing The Core and I was looking at one of his RMFs... I quickly updated all of my maps with the correct setup.
2. For the longest time I thought that info_landmark entities had to be in the EXACT same spot between maps. Again, I never realised the proper use of info_landmarks until Archie looked at some of my maps for The Core and asked me why some of them were WAAAY off in the corner of the grid. He laughed.