and the TSA is not going to be amused by any explanation . . .
I used to do a lot of European business travel - typically in/out of Frankfurt. BA, at least, has/had staff that would question you while you were waiting to check in. they had a whole series of questions about your baggage, booze, where you were, weapons and etc. when they finished they'd put a sticker on the back of your passport and on the luggage.
so - and you can see this one coming - once upon a time I bought two Wuesthof knives to bring home - an 10" slicer and a 6" paring. they were packed my bag. so the prequestioning staff did their usual thing. the 'old' stickers were still on the passport, and the bag for that matter - so methinks they get a feel for folks that been there done that before.....
the very nice dude finishes his questions, stickers me up, says have a nice day - when I mentioned: Dear Sir, you did not ask me if I had any weapons, knives, swords, etc. and in fact I have two knives packed in my bag. at the time I was able to quote back word-for-word the "normal questioning"
thought he was gonna' die on the spot. different stickers, didn't get arrested, whatever . . .