A mom’s emotional Facebook post is highlighting the importance of foster care.

After dropping off her foster child en route to his new home, Rachel Hillestad noticed he’d left his Cookie Monster toothbrush in the car. The mere sight caused her to burst into tears.

In this moment, Hillestad posted a photo of the toothbrush, along with a powerful caption.

”I’m sitting here in a parking lot sobbing my guts out,” she wrote. “He was mine for two and a half weeks, but those days and nights saw him smile, sleep through the night instead of freezing awake in terror, swing for hours on the swings my kids take for granted. He called me Mama, and I told him every time I left that if I said I would come back, I would.”

Hillestad said that people often tell her, “I could never do foster care. I would get too attached.” But, she says, she does get attached, and that’s the way it should be.

“I wonder where they are now,” she said of her foster children. “They visit me in my dreams, and sometimes I wake up with a wet face. It hurts. Sometimes in those moments it hurts to breathe.”

There’s something more important at stake though, she added. “I’d rather these sweet babies know my love than never know it,” Hillestad said.

“There is absolutely no reason that an 8-year-old who watched his mother be murdered not know the love of a stranger,” she added. “It’s absolutely criminal that a 2-year-old sit in a social worker’s office for two days in dirty clothes because I’m afraid I’d get too attached. I got attached. Getting attached has been the greatest pleasure and honor of my entire life.”

The mom’s post received nearly 75,00 likes. Hillestad, who lives outside Kansas City, Missouri, told The Huffington Post that she and her husband Scott have fostered 70 children over the past six years.

“Some were abused either physically or sexually, some neglected, some testing positive at birth for one or another illegal substance,” she said. “Some have been longer term placements, some have been respite placements, which is where another licensed foster parent can have the children for a few days so the main foster parents can have a break.”

“Foster care is very rewarding, but it is also tiring,” she added.

Hillestad and her husband initially became foster parents due to infertility issues, but their reasons changed over time.

“It became a matter of, ‘How can we as a society, this society that is supposedly the richest and most prosperous nation in the world, allow this to happen to our children?” she explained.

“How can we allow 3-year-olds to sit in county offices overnight while we watch Netflix after a ‘hard’ day?” the mom continued. “I think ‘hard’ is being beaten within an inch of your life. ‘Hard’ is wondering if you’re going to eat today. ‘Hard’ is not, ‘Oh, I have to go to the grocery store again because we’re out of milk.’”

Hillestad said that foster parents need flexibility and compassion. And kids like the foster son in her Facebook post often move to new homes for a variety of reasons. Sometimes relatives come forth who can take care of the child. Sometimes other foster homes that are better suited for child’s needs or able to accommodate larger sibling groups become available.

“In this situation, it was the best case scenario for him to move,” she explained.

But, she added, “There are a hundred thousand more just like him, kids who could better use that extra guest bedroom many Americans have than the once-a-year holiday visitor.”

Although the goodbyes can be painful, Hillestad ― who also has three kids of her own ― said she is committed to fostering more children. “I know there will be another hello, and another, and another,” she said. “I also know that some day, 30 years down the road, there will be a knock on my door, and the years and tears will melt away ― and I’ll see a face I’d recognize anywhere.”

Since her Facebook post went viral, Hillestad has received messages from former and current foster kids and foster parents. “It’s been this amazing gift to see this beautiful web of humanity, all stretched out before me and glistening with hope,” she said.

The mom also launched a T-shirt sale to benefit Together We Rise, a non-profit dedicated to helping kids in foster care.

Ultimately, Hillestad hopes her post will be a call to action. “If you’re living and breathing, if you’re blessed to have a beating heart, get out there and make a difference,” she said. “Take that first step. Go to an informational meeting. You’ve heard the commercials: you don’t have to be perfect to be a perfect parent. It’s true. These kids are literally filling government offices and it’s our duty to respond.”