And then there’s all that trouble ordering the cake . . .

Adolf Hitler’s birthday is Friday, and here I am without a present.

Or a person to give it to — well, there’s Arthur J. Jones, the sorta-Nazi running for Congress on the Republican ticket. We’ll get to him later.

April 20. Hope it passes peacefully. Ever since April 20, 1999, when Eric Harris and Dylan Klebold murdered 12 fellow students and a teacher at Columbine High School, kicking off the current era of mass shootings at schools, there’s been a certain clenched expectation to the date, even though the pair actually planned their attack for the 19th, but delayed a day to collect more ammunition.

The media unhelpfully increases the dread by lumping in April 19 — it’s so close! — since that’s the date of Timothy McVeigh’s 1995 bombing of the Murrah Federal Building, which killed 168 people in Oklahoma City. But McVeigh was thinking, not of a pre-birthday blow-out for Hitler, but to avenge the deaths of 80 Branch Davidians in Waco, Texas, on April 19, 1993.

Which is why it’s good to pay attention to anniversaries. Terrorists sure do.

The bright spin: at least they’re remembering history. A poll released last week shows that 41 percent of Americans, and 66 percent of Millennials, can’t identify what Auschwitz was (oh, sorry kids: concentration camp — 1.3 million people killed there. Notorious in its day. Now, obviously, not so much).

This news shocked me not at all. Grappling with unpleasant facts has fallen out of favor for wide swaths of the country. If you can ignore the increasing toll of global warming, gun violence and a broken health care system, then shrugging off some dusty crime in Europe 75 years ago is easy.

So happy, umm, Hitler’s birthday! He was not without good qualities, you know. Hitler was a decorated World War I combat vet, which might explain why Arthur Jones begins a letter he sent to the Chicago media, “I am first and foremost, an American patriot who fought for this country as a combat veteran in Viet Nam.” He focuses on “hostility” he faces due to his “personal opinion that the ‘Holocaust’ is a greatly overblown non-event” that Jews use to grub money.

He included his phone number. I couldn’t help calling. He seemed surprised.

“You’re the only one who bothered to respond,” he said.

We spoke for a long time. His general tone could be described as “compressed anger.” When I asked Jones if he is a Nazi, he launched into a lengthy exegesis that I interpret as “Yes, but…” He seems to think that not being a card-carrying member of the Nazi party right now is an important distinction.

I had to ask: Are you celebrating Hitler’s birthday this year?

“No,” Jones said. “But I had three very successful parties for him in the past. It wasn’t just for Hitler’s birthday. It was an opportunity to get together with like-minded people.”

Did you have a cake?

“Of course.”

What did the cake say?

“‘Happy birthday Adolf.’”

My work here is done. I did throw my own…not celebration, but a kind of commemoration, pulling down my copy of “The Essential Hitler” and reading. The introduction by Charles W. Sydnor points out how Hitler was “never satiated by any triumph, achievement, political victory,” and frequently referred to himself as a “world historic genius.”

Marcus DiPaola/Sun-Times

Hmm. I would never compare any current American leader to Hitler — it’s amazing how offended people can get if you suggest a politician they support echoes Hitler, while at the same time seeming not to care at all that the reason for the comparison is that he says the same stuff Hitler did.

Besides, our current American scene is at worst a low-grade, diffuse, weak-tea Hitlerism. We’re still safely in Weimar America. For now.

Who knows what will happen? Friday isn’t just Hitler’s birthday. It’s also 4/20, the informal Independence Day for pot smokers. It doesn’t seem impossible to juxtapose the fading memory of World War II’s horrors with the rise of the American marijuana industry and anticipate some future melding of the two. Maybe billboards will someday feature Rasta Hitler, his dreadlocks tucked into a visored cap, his strap t-shirt emblazoned with a red, yellow and green swastika. Grin addled, he proffers a joint and commands, “Follow your Weedenfuehrer! Mellow your megalomania with a Sativa Blue Dream Blunt.”

Sure, a few marginalized Jewish groups will complain. Then the world will shrug and move on, as it always does.