Well where can I start. Maybe saying that I have never made any mistakes that I cannot repeat later on, except a few biggies:
1. Fueling up my new Turbo Arrow back in 1979. was in a hurry (very bad) finished up jumped in took off popped the gear and looked right to see fuel coming from my fuel cap, looked again and saw the cap leave the wing, this I will not repeat soon.
2. Took my first helicopter flight lesson in an R44 had a passenger in the back taking pictures out of the open door, was wearing glasses at the time and a baseball cap, turned my head and my $700 Titanium glasses went out the back door straight into the tail rotor, glasses strap from now on, I can't see beyond the panel without glasses, very interesting ride. chipped the rotor. Not good.
3. Changed my own oil in my 60' power boat, transmissions and mains to Ames Oil synthetic. Thought I had completely filled them, decided to take the boat out for a test ride by myself, this was in December in Annapolis Md. untied, put the boat in gear and left the dock, went to place the shift in neutral so I could maneuver out the marina and found that I had no response from the transmission, you can figure the rest, never actually filled the transmission fully enough to apply pressure to engage the transmission.
4. Picked up my new boat in Fort Lauderdale Florida one summer, really hot July. New boat right out of the factory (Blackfin) and started back to Maine for a great summer ride, encountered a bunch of new boat issues. noticed a smell in the bilge opened it up to find raw black water in the entire bilge, plumbing had come apart. Decided to handle this quickly and efficiently had a shop vac on hand, placed it in the bilge and started filling it up, going like crazy, until the ball stop flies up and stops the flow, if you have ever used your shop vac to clean up water you know what happens when you have over filled the shop vac, it is not pretty especially when you are standing right over the vent.
These are just some of the lesser mistakes.
Knock on wood the bus has been less of a learning curve so far.