just didnt think to take my passport. I was in my 20's and sorta dumb and honestly I dont recall Canada had ever checked for passports prior to that. So I get to the border crossing the guard has all sorts of attitude immediately which I found annoying and asks for my passport. I look at him kinda shocked and say I didnt bring it. In a super snooty tone he says "sir are you aware that Canada is a foreign country for Americans?"

Didnt sit well with me so in a similarly snooty tone I replied back "Really? For all these years I thought American owned Canada or it was like a territory of ours?"

That didnt go over very well......and I got to spend a few hours there as a result as they searched my car, my bags, checked my records, confirmed my hotel reservation, looked to see if I had drugs, made me sit and wait and wait and wait, etc. Eventually they decided I was no threat to Canada and allowed me in, with no passport. But I think my 20-something flippant attitude didn't go over well with the similarly flippant 40 something border guard.....