I have a checklist on my tablet that I use before leaving the house but the fact is it is too long and easy to miss something. After reading all these posts I am going to make a Critical things to check list and post it on the dash. I did once forget to remove the tire chocks but that just stopped me from going anywhere.
I did forget the drain plug in a boat once, luckily the boat filled with water fast enough to stop it from floating off the trailer and I was able to pull it back out and drain it. After that the plug stayed in and I only took it out to drain and put it right back in, and I still checked it every time I hooked up the trailer.
Glad to hear you were able to get it fixed without any permanent damage.