The morning after we moved into our new house, I woke up to shoulder-high stacks of boxes and promptly fled to the nearest coffee shop with my 4-year-old son. As I sat there moping over a lousy cup of tea, I spotted a mirror image: a woman, with a young son, who looked as stressed out as I felt. As our kids lined up chairs to make a train, she laughed and said, “We’ll survive this day better if we sit together.” Marissa and I have been friends ever since, and my move — which seemed so difficult at first — ended up being a breeze.

My husband teased me that evening when I told him how relieved I was to have made a friend in our new town. He didn’t really get it, I thought — moms make friends not just because it’s convenient, but also because it’s utterly essential to our health and happiness. Here are five reasons why.

1. They Help You De-Stress

Research supports what we already knew: When the going gets tough, guys grit their teeth, but we call our girlfriends. While men’s bodies typically react to stress with a “fight or flight” response, women are hardwired to seek social contact with other women. “Our physical and mental health depend on having close relationships with people we can turn to, especially in times of crisis or stress,” says Tara Flack, EdD, an expert on women’s health at Penn State. What’s more, the quality of a mother’s intimate relationships is one of the strongest predictors of her child’s healthy development in the early years, she says. “Mothers of young children need to know they have someone to turn to when things seem overwhelming.” Kate Miller of Minneapolis, considers herself a very private person, but knows she can tell her friend Jane anything. “She frequently reminds me to let my husband do things his own way when he’s taking care of our 4-month-old daughter so that they can develop their own relationship,” Lauer says. “When I talk things over with Jane, I always feel reassured.”

2. They’re Not Your Mother

Joan Erickson, of Wayzata, adopted her first child when he was 5 weeks old. Everything went smoothly until, late one night; she mixed up formula in a bottle with a plastic insert and warmed it in the microwave. “As I was feeding him, I noticed this tiny writing on the plastic that said ‘Do Not Microwave,’ and I absolutely panicked,” she confesses. She immediately picked up the phone and called her mother, who said, “Honey, you’d better call somebody else. I haven’t done this in a while.”

Basics like bottles and diapers aren’t what they used to be, and your friends can give advice on matters your mother never had to worry about. You may want to sleep with your infant or carry your toddler in a sling, while your mom argues that babies should stay in their cribs and make good use of that playpen. Or your mother may advocate staying home full-time, while you’re already scouting out the best daycare. “No matter how hip she is, your mother probably has a selective memory about her own parenting track record,” Dr. Flack says. Being a mom is more complicated than it once was, and we need our friends to remind us that we’re not the only ones failing to meet some impossible ideal of motherhood. Finally, many of us, no matter how much we love our mothers, don’t see them as paradigms of parenting. We want people who share our values, and sometimes that’s just not Mom.

3. They’re Always Brutally Honest

Should you invite 100 people to your 1-year-old’s birthday party? Were you wrong to tell your mother-in-law that she can’t feed your toddler hot dogs? How much should you spend on a present for your kid’s preschool teacher? Can you wear that strapless black dress even though you haven’t shed those last 15 pregnancy pounds? Your friends will give you the most truthful — and tactful — answers.

As a project manager with a busy work schedule and three children, Abby Fenlon, of St. Louis Park, depends on her friend Virginia to give her the straight scoop. “Virginia is home full-time and is totally on the pulse of what’s going on in our community,” says Fenlon. “She’s fabulous at etiquette, and she helps me realize what’s appropriate. For example, yes, I do need to let my twins’ classmates bring their older siblings to our birthday party — that’s just what people do in our town.”

4. They Get It Like Your Husband Can’t

Emma Walker, of St. Paul, describes her husband as “a totally sensitive guy.” Still, after having her first child, she realized it was impossible for him to understand some of the things she was feeling. “That’s why it’s such a relief to talk to a mom friend who gets it,” she says. Your husband faces an insurmountable gender gap when it comes to fully understanding why you worry about leaking breasts, blow-dry your hair before going to the grocery store, or lie awake at night because your daughter’s preschool teacher called her “timid.” But other mothers can validate the fact that mothering is hard work, says Pam Jordon, PhD, author of Becoming a Parent. “What’s more, women who lack close friendships are sometimes so needy that it can create conflicts in their marriage,” she adds. With a friend, there is no limit on how long you can analyze an awkward conversation you had with an intimidating mom, but drilling down on such details with your husband is not going to make for a fulfilling exchange.

5. They’ve Been There, Done That

It’s great to be able to commiserate on a daily basis with mom friends who have kids at the same age and stage. But it’s an added bonus to have friends with kids of different ages: “With friends whose children are younger than yours, you can be proud of what you’ve learned and appreciate what’s gone by,” says Dr. Jordon. Friends with older children can clue you in on what to expect.

Lindsay Shea, of Edina, is grateful to have met Diane, a woman in her mothers’ group whose son is older than Shea’s daughter, Olivia. “It’s incredibly helpful to see what Olivia’s next step is going to be and also to realize that there’s a big range in what’s normal for babies,” says O’Shea. She also joined a breastfeeding support group. “When Olivia was born, I thought I’d just give nursing a try, but now that I’ve been hanging around with moms who are still breastfeeding their 1-year-olds, they’ve inspired me to continue nursing too,” she says.

Most important, though, many of the connections you make with other women through motherhood — even if they started out at the playground — may last a lifetime. “It’s a wonderful camaraderie unlike anything else,” says Emma Walker. “My mom friends and I started out going to each other for parenting advice, but now we talk about every aspect of our lives. I don’t know what I’d do without them.”