I've failed to use checklists a few times because of forgetfulness, and the moment I realized what happened, I mentally slapped myself.
There's nothing 'cool' about flying without a checklist, it's a tool to stay alive. You don't use your fingernails instead of a screwdriver just because 'screwdrivers are for n00bs'.
During my training, I remember once when I landed in the Warrior while flying solo and realized that I had never done the approach checklist. This means that, in addition to other stuff, my fuel pump was not on and I hadn't toggled tanks. I was lucky in that my active tank was still pretty full, and that the mechanical fuel pump didn't crap out, but I was chilled at the thought of what would have happened if it hadn't been one of those 'lucky days'.
The 'Killing Zone' book I read about what kills pilots lists complacency as a major killer. It describes a situation where, say, someone skips a step in a preflight and has a successful flight. Later on, they skip it more and more as 'optional' because the repeated incident free flights train them that it's not a big deal. ...right up to the time when something happens that the step would have caught. After reading that, I mentally challenge myself on every aspect of flight that I can. I don't want to be one of those guys who can't pass a check-ride one year after they get their certificate (a significant portion of new pilots let their skills lapse as time passes, an FAA study found).
These guys are dead and can't defend themselves, but it sure sounds like this could have been prevented.
