Try being a Canadian and going the other way!
I had to bite my tongue to not say “I’m a citizen, you have to let me in.”
The US is always a PITA, esp. after long international flights. One time they flagged me for "smuggling halogen headlights" or something and searched ALL of my stuff. Missed my LA-DC flight because of it. And I'm a white, clean-cut US citizen.
Do you bring back any food ?
(I had a undeclared box of cereal in my backpack)