(The Washington Post/The Washington Post)

They [mess] you up, your mum and dad.

That’s the opening line of a poem by Philip Larkin. Well, I’ve censored it for a family newspaper, but I think the point comes across: What happens when we’re little affects us when we’re big.

I’ve often thought of that while interviewing clients of Sasha Bruce Youthwork, a charity that helps homeless young people in our area and is a partner in The Washington Post Helping Hand.

I talk with these young people at different places: the Sasha Bruce House, an emergency shelter on Maryland Avenue NE; Promise Place, a longer-term shelter in Capitol Heights, Md.; and ReGeneration House, an independent living program in Southeast Washington.

I’ve met them at the Sasha Bruce drop-in center on Eighth Street SE, where, on weekdays, homeless kids can take a nap without worrying that someone will steal their stuff, where they can wash themselves and their clothes, where they can get a meal.

Of course, what I want to know is: How? How did you end up without a home?

I imagine my own children and how there is nothing they could do that would harden me so much that I would turn them away. How could I live with myself not knowing where they were spending the night — or knowing that it was on the streets?

So how?

“I didn’t get along with my mom” is what these Sasha Bruce Youthwork clients often say.

Or: “My mom was too strict.”

Or: “My parents didn’t like my friends.”

I’m sure that’s true in some cases. And it’s probably the simplest, least painful way to explain it to a strange man in a suit and tie who has taken out his notebook and asked you to spill your guts.

But it often plasters over the real reason.

I’ve interviewed several Sasha Bruce clients who — after saying, “I didn’t get along with my mom” — got quiet, blinked back tears and then said that they had been sexually abused in the home, abuse that their mother knew about and did nothing to stop.

Some of their mothers did not believe them, or believed them but felt it was their own fault, believed that the abuse — by an uncle, stepfather or cousin — was something they had brought upon themselves.

So they ran away, preferring a friend’s couch, an abandoned house or a homeless shelter to a home of anger and distrust.

“That situation is very prevalent,” said Robert Bell, who runs Promise Place. “When you get these girls in here who are having conflicts with their moms and no relations with their dads, it makes them feel like they’re growing up on an island of isolation,” he said.

Part of his job is to mediate with parents and see whether the child can be reunited with them.

“We try to bring the family to some level of homeostasis, so they can have some level of functionality,” Bell said.

That doesn’t always happen, and so Sasha Bruce Youthwork provides the support that these young people never got at home.

Scars run deep in other areas, too, Bell said. Some of his clients are teenage boys who are, in their mothers’ words, “acting up.” They are skipping school, getting in fights, getting arrested, getting high.

Their home life is currently stable, with their mothers holding down jobs, going to church, keeping a nice house. Bell said, “I say to them, ‘Don’t tell me what’s going on right now. Tell me how life was when he was 3 and 4 and 5.’ ”

And then the history comes out. “Then, I was still on drugs,” the mothers tell Bell.

Or: “I had an abusive boyfriend living in the house.”

Or: “We were homeless.”

Bell said, “You’re just getting the residual effects now. It doesn’t just heal itself. . . . You’re on top of the world and you expect your son to be there, but the underlying issue hasn’t been dealt with.

“That’s the fire we have got to deal with again and again.”

This is the last column I’ll be writing about Sasha Bruce Youthwork. The Post’s 2016 Helping Hand fundraising campaign comes to an end this week. Soon, we will pick three different local charities to highlight starting next fall.

I end on what may seem a somber note, but it’s a necessarily honest one. The causes of youth homelessness are painful. Most kids don’t run away just because of a strict parent. They mess you up, your mum and dad.

And that makes what Sasha Bruce Youthwork does all the more important. Each year it provides safe homes, life-skills classes and workforce opportunities for more than 1,500 young people. To make an online donation, visit posthelpinghand.com. To donate by mail, make a check payable to “Sasha Bruce Youthwork” and mail it to Sasha Bruce Youthwork, 741 Eighth St. SE, Washington, D.C. 20003, Attention: James Beck.

Twitter: @johnkelly

For previous columns, visit washingtonpost.com/johnkelly.