Also happy nothing untoward has happened to you, but have to agree-at least everyone should know the law and the "potential"consequences of their action.
I also play by the rules coming home- declare, do the math calculations in both currencies and coded according to type of purchase.This has stood me in good stead- personally, I think they just want to get rid of a crazy OCD lady, but regardless I have always been on the receiving end of "Thank you for your honesty, please just go through".
Whatever you choose to do, know the consequences and be willing to deal with them.