9-11, give me a break.

[Tiberius]

9/11 wasn't a "defeat" because it wasn't a battle or even part of a war. It was a tragedy, and is remembered as a tragedy just like many others are. Innocent civilians lost their lives...that's why we remember.

We pull the same thing every year with Pearl Harbor, Divi Tiberio.  We weren't at war then, either.

I'm not sure what your point is. We remember Pearl Harbor because so many people died in a horrific act, the same reason we remember 9/11. Other countries do the same thing with national tragedies. In November, I'm sure France will remember the attacks that happened the year before. Every year, the Japanese remember the people who died in Hiroshima and Nagasaki. So to answer your original question, yes, this is pretty normal behavior. Honestly, I'd find it very strange if people didn't have some sort of remembrance for people who have died.

But, WTF.  We celebrate the end of WWI with mattress and car sales.

There's a big difference, in my opinion, between remembering a day when a lot of people lost their lives (a bad thing), and remembering a day when a ceasefire was declared or a war ended (a good thing). One is mourning, one is celebration. Sales are a form of celebration in retail, so I'm not sure what's so WTF about it.