Rendering: Adam Pardee/STAFF.

My 20-year-old daughter went out to DNA Lounge in San Francisco Friday night to see a DJ I don’t know/understand perform. It apparently was gropers-get-in-free night, as her fellow club-goers – the male ones – were feeling particularly grabby.

This is exactly why I spend a considerable sum each month for her 14-year-old sister to learn ju-jitsu: so my youngest becomes totally comfortable with physical counter-assault and smashing boys’ faces into the dirty and infectious ground until they absolutely require professional medical assistance.

If necessary.

Yes, I am encouraging violence, and gleefully so. Because many of you bad parents haven’t inoculated your sons against casual idiocy (C.I.), so I blame you if they need their groin kicked into their throat. We have an outbreak of C.I. happening in this country right now. Maybe there’s a new exotic brain virus going round.

One young man in question, without being properly introduced to my 20-year-old at DNA Lounge, kept touching her until she had to yell at him (knowing my daughter’s verbal capabilities, I’m sure it involved a threat and a string of unpublishable epithets she probably learned from her father watching the Raiders lose. I don’t totally absolve myself in all this).

I’m also sure she’d already looked at him multiple times with the same expression someone does when they pull six months of old hair from the shower drain. I’ve seen the look – usually when I threaten to play my music in the car.

But because this poor brain-addled club-mongrel suffers from such a serious case of CI, being yelled at by a stranger wasn’t enough to prevent the reptile from making a fourth attempt – fourth – at getting his arm around my daughter’s waist.

Being that I failed to convince her to learn how to break a stranger’s arm as a child – I tried; she was busy building fairy traps or something – she did the 267th next best thing and flicked him in the face, like he was some misbehaving animal. Which I guess hurt his feelings and was more attention than he deserved, but not nearly anywhere near the permanent crippling he really deserved. At least he got the hint and went away.

Part of the problem is that we treat grabby young men like misbehaving animals. Why must young women who spent $30 to get to a club to watch a musical act they theoretically enjoy instead have to be bothered with stupid boy-mongrels who deserve crippling?

And even worse – much much worse – why do their poor fathers have to hear the stories the next day?

So here’s the shocking but obligatory statement of mitigation: I was once a stupid young man who deserved frequent kicks to the groin. Sometimes I awake during the night screaming in terror after having a nightmare of all the girls I wronged lining up to administer karma.

But I was able to learn. And, even then, I never understood touching women I didn’t know into liking me. Like men sending women unsolicited penis photos: Why? Does that ever work? And, even if it did, why would you want it to work?

Don’t touch anyone unless they give you clear permission (if it’s my daughter, I’m going to need to see something in writing and notarized). Why is that so difficult?

The symptoms of casual idiocy aren’t just sexist – they can be racist as well. South African musician Jonathan Butler was recently in town to do a show and dined at Goose & Gander in St. Helena. After he paid his bill, a manager followed hm to his car to allegedly make sure he left the server an adequate tip.

What?

Butler said on social media (in a now-deleted video) he left a generous tip and, when the shock wore off and the CI-infected manager was back in the restaurant, went back in to confront him. This guy had a fan in Nelson Mandela, and he had to deal with prickly wine country racism.

I hope he flicked him in the face.

I have about 300 male white friends who, despite swearing otherwise, don’t live in this reality. Being defensive white men, they might ask how this is proof of racism. To which I say: Don’t be stupid. None of us have ever been followed to our car by a restaurant manager who suspected we were guilty of light tipping. And most of us used to go out in public looking like Motley Crew roadies.

Mr. Manager could’ve simply looked for the tip. He could’ve asked the server. He could’ve made sure he paid his employees better. He could’ve not been stupid. Or he could’ve treated the Black customer the same way he would’ve treated a white customer whose return business he wanted.

It’s time to stomp out casual idiocy.

Follow music critic Tony Hicks at Twitter.com/TonyBaloney1967.