My wife carries a big (4" blade) folding knife in her purse. Makes her feel safe. Anyway, she texts me from the airport after taxiing there from home, telling me she forgot it was in her purse and asking me what to do about it. I tell her to find a place at the airport to mail it home. This is a high quality Benchmade knife I bought her, well over $100 to replace.
Eventually she gets around to telling me she is already through the security checkpoint. Facepalm! She ended up mailing it back from her destination. I have no idea how they missed such a full-size folding knife in the scan.