I mean, its my plane, and I know I put it away in the locked hangar in flyable condition, so why do a controls check to confirm the controls aren't cross-rigged? And why check the fuel, when I know I always gas it up before putting it away.
I pulled that stunt with a gun. After shooting at the range I unloaded my gun like I always do, and zipped it up in the range bag. When I got to my car I realized I didn’t have my regular concealed weapon and was facing a long drive alone at night, so I unzipped the range bag, loaded the gun, and left it there within reach. When I got to the house I zipped up the bag to carry it into the house, put it down and forgot about it.
Well you know what happened. Later when it was time to clean my guns, I unzipped my range bag and there was my gun
that I always unload at the range. Totally forgot about what I’d done in the car. Because I “knew” the gun was unloaded when I put it in the bag, I picked it up and started fooling around trying to take it apart to clean, muzzle sweeping myself all over the place. It finally dawned on me, with horror, why it was not coming apart - it was loaded with one in the chamber!
I had broken the first rule of gun safety. But the second rule saved me - I kept my finger away from the trigger at all times. You can bet I never, ever will break the first rule ever again.
It’s the exact same thing with your airplane. You can never assume anything even when “I’m the one that put it away last.” The thing that messed me up with the gun was that I’d broken the routine and done something unusual and different. Memory is a tricky thing. When you perform the same act over and over, they tend to run together in your mind and you will “remember” doing something the usual way even if you varied one particular time.
One of my CFIs screwed up big time with this, looking into the fuel tank and “seeing” it full, because he was so used to always seeing it full. You get in a hurry and don’t mindfully pay attention when you preflight, your brain plays tricks on you, when it comes to things you’ve done repeatedly, it tells you it is like it always is. And then one day it isn’t and you fail to notice.