The shelves at a Target in Arlington, Va., a few days before school started. (Theresa Vargas/The Washington Post)

Pink erasers. That’s what you won’t find when you’re one of the last parents to hit the back-to-school aisles.

Or construction paper, size 12-by-18.

Or composition books filled with graph paper with large squares, measuring 7-by-9¾ inches.

If ever you start feeling too confident as a parent — maybe your child asked for a book for his birthday or she offered to help vacuum out the car without needing a ride somewhere — then just wait until the last minute to buy school supplies as I and other parents did before classes started in Virginia and Maryland this week. There, parental confidence is at its lowest.

There, we all hang our heads as we shop.

We hang them in shame, yes. But we also hang them because we have to continuously look down at lists that seem unnecessarily complicated while trying to read labels on almost-empty bins that often don’t hold what they promise.

There, we listen to one another’s sighs and know that they are not the type that plead for attention, the kind that say, “Please ask me how I’m doing because I need to talk.” They are the type of sighs that are muffling curse words and say, “Leave me alone because right now I hate the world and I especially hate boxes of 12 colored pencils because I need a box of 24. Make that three boxes of 24.”

The sighs are asking, why for the love of morning glories (though your mind won’t edit vulgarities in that way) does my child need three glue sticks and three liquid glues? Doesn’t all glue, no matter what form or color it comes in, stick things together?

And why do I need four “pink” erasers when the entire purpose of them is to remove color from a page?

I found a pack of six erasers. Two were pink. Four were other subdued colors. I grabbed it and considered whether that slight stray from the list would matter. Since my sons’ school doesn’t want us to label our children’s items, I pictured the pack thrown anonymously into a pile of pink rectangles and chosen only when those other rule-abiding erasers were rubbed down to nubs. I then, naively, put down the pack and decided to keep looking.

It took maybe three minutes before I realized my mistake. All the other packs were gone, their bin picked bare. I went back to find my mismatched pack of erasers and by then, it was gone. Some bolder, forget-the-rules mom had picked it up. Or maybe her child’s school rightly didn’t care what color she bought.

I know, I know. There are, of course, ways I could have avoided this ring of parental hell.

I could have been among the uber-prepared parents who ordered a PTA-prepared bag of school supplies at the end of the previous year. It’s such a smart service for the organization to provide. I wrote down the deadline and intended to place an order. Then educational angst started nagging at me and I found myself considering whether we should try to switch schools, weighing whether a language-immersion, science-centered or Montessori program would benefit my children more, and the deadline for the school-supplies service passed.

I realize I could have also shopped early.

But every time I had previously passed those aisles filled with dangling backpacks and fruit-scented markers, I had two squirming little boys with me, and the idea of trying to find a blue folder with prongs and a red folder without prongs, to coincide with their favorite colors and their school lists, was enough for me to keep pushing my cart.

Guess what happens when you wait? You don’t have to search for a blue folder with prongs or a red one without — because neither is left. Apparently the least favorite colors of children, or maybe it’s their parents who pass on them, are pink, purple, white, black and gray. This is not based on any scientific study but on the sad remnants on the shelves at an Arlington-area Target two days before school started.

I filled my cart with black and gray folders to match my mood.

I know there are many parents who will not be able to relate to this frustration.

They are the parents who fill their back-to-school bags with folders the colors of oceans and sunsets and who I am thankful exist. They are the moms and dads who program all the early-release dates immediately into their devices and whose children I hope mine befriend because then I know who to call when I can’t find an email or have a ridiculous question, such as whether a green shirt will work for picture day. (It won’t, apparently. Unless you want your child to appear a floating head because his body disappeared against the green-screen background.)

That’s one of the best, never-mentioned benefits about the back-to-school season. Our children are not the only ones who have a chance to make new friends who are different from them. We do, too.

There are few other situations in the Washington region in which adults from various cultural, political and philosophical backgrounds (and who also happen to carry different organizational skills) are randomly tossed together. Those differences can be even more stark, and include a spectrum of socioeconomic situations, when children attend schools that draw from different Zip codes.

In this region, one of the first questions most of us are used to hearing is, “What do you do for a living?” In the classroom setting, during those open-house nights or on the first day of school, that question matters so much less than, “Where did you find 12-by-18-inch construction paper?”

Or “What books helped you get him reading so well?”

Or “How do you get her to eat dried seaweed like candy?”

The truth is that we all have our parenting weaknesses and strengths, and the honest, no-holding-back conversations I’ve had with parents who have shared their own and have let me share mine without judgment have been one of the best parts of having children old enough to attend school. I guarantee you that the mother of the child who brings broccoli in her lunchbox most days has moments of feeling inadequate. But in order for her to feel free to admit that, we need to stop parent-shaming — which happens way too often nowadays — and we need to be more honest about our own deficiencies and insecurities. We need to be able to discuss screen time without feeling as if we’re straddling a third rail and be able to pull out snacks without worrying if a fellow parent, who may not know about the dozen allergies a child endures, is making a mental note of the sugar content.

How will we figure out the best ways to talk to our children about major issues such as race and politics and why their Nike caps are now a statement about both if we can’t discuss freely how those subjects were handled well, and not well, in other homes?

I don’t remember my parents caring what other people thought about them when we were growing up in Texas. They gave us swigs of coffee in restaurants before we were old enough to go to school. Maybe that finger-wagging instinct has changed with time as studies have taught us more about child development, or maybe it’s just more noticeable in a place such as Washington, where image means so much. Here, it’s not unusual for a parent to read the ingredients on juice boxes for 20 minutes before deciding which to buy for a party, and even then, there might still be a parent who questions whether juice should have been served at all.

Because of this column, I probably see the judgment on an amplified level. When I wrote about my child’s first dead fish, someone wrote to chastise me for being among the “clueless humans” who went to a pet store. When I wrote about having three miscarriages, a line I included about my sons being typical “cross-stream-peeing” boys prompted someone to send an email saying, “When you became a mother you assumed a sacred trust to protect your future adult children’s’ dignity and right to privacy. You violated that trust.”

On a recent afternoon, during the back-to-school physicals for my sons, the doctor asked one of them, “Do you play any sports?” and I actually felt my blood pressure rise. My son doesn’t. And despite his healthy appearance and the amount of time he spends running outdoors, chasing bugs and balls, I worried that his answer would immediately label me a failed parent. But when my son said “No,” the doctor looked at me and said, “Good for you for resisting that pressure.”

He got it. As long as kids are happy and healthy, there are sometimes no wrong answers because children’s personalities and those of their parents are all so different.

That day I walked through Target with my head down, I wasn’t alone. There were at least 10 other mothers picking through the same scraggly remains as I.

The reality is that none of us may ever send our children to school with blue folders, but that matters so much less than what will come home in those black and gray folders we bought instead.

There, we will find homework, permission slips and art projects made on 12-by-18-inch construction paper. And, if we are lucky, we will also find invites to play dates and birthday parties where maybe our children won’t be the only ones forming valuable friendships.