I recently took a folding knife with a 4-inch blade through security undetected. It was an accident by me - it was in my carry-on - which was x-rayed - and I didn’t realize it was in there until I got home and unpacked. Whoops.
Same here. After returning home from a trip, I dumped out my purse looking for something else when I saw the pocketknife and nearly fainted. It was given to my by my grandfather and would have died had it been confiscated. I couldn’t believe I forgot to remove it from my purse PRIOR to flying. I went through security 6 times on that trip.