Number of times I've accidentally carried an easily lethal-sized knife on a flight without airport security noticing in the last year: Once and now twice:

(I discovered this in my bag this morning, after my flight from Denver to San Francisco yesterday.)
Number of times I've accidentally had a knife in my bag that security did notice in the last year: Zero.
(I discovered this in my bag this morning, after my flight from Denver to San Francisco yesterday.)
Number of times I've accidentally had a knife in my bag that security did notice in the last year: Zero.