I wouldn't necessarily say that there are no NEW mistakes. New could mean NEW user making a mistake, or an old user having to come to the rescue of someone who made a NEW mistake that they personally would not have.
Back in the 80's, one of my High School friends had an early 80's Mercury Lynx essentially a Ford Escort. I get an SOS call one afternoon from her. She told me that her dad tried to help her do an oil change, and he accidentally drained the transaxle fluid instead. I had done oil changes on her car before, so I obviously knew where the drain plug for the Oil pan was. However, upon arriving at her dad's house, I discovered that in order to access the transaxle fill hole, I was going to have to remove a motor mount and rig up a hose to get the fluid from the bottles to the hole. Then of course reinstall the plug. Did I mention that by the time I was able to undo, refill, and replace the mount, it was getting dark out in their driveway. MY patience was obviously tested as the oil change still had to be performed. This was one of those F U @ Ford Engineers oil changes I hated how they designed the car. THE dang filter was located on the SIDE of the transverse mounted front wheel drive engine in the tightest of places between the firewall and engine. And to change it properly with a hot engine was also the worst, because it sat directly above the exhaust pipe. I felt like I was shoving both arms as far as they could go and barely able to get strength or a filter wrench to turn old filter off.
When she finally moved from MD to Fullerton CA, I no longer had to worry about that car.
I also never forget that her Engineer dad messed up a simple oil change.
