A few weeks ago, I was playing with my then three-year-old son, Jude, when I noticed an eyelash on his cheek. Playfully, I asked him to make a wish. He squinted his eyes, clearly focused on his wish, and when he was done exclaimed, “I’m so excited!” Expecting him to have asked for a unicorn for a pet, or a purple dog, I explained that not all wishes come true. But that’s not what he wished for. He said, “but mommy! This one will come true because I wished for all my friends to come to my birthday party.” It felt like a punch to the gut as I still hadn’t gotten a single RSVP to his party.

This year was my first time organizing a party for Jude, making it a learning experience on many levels, but there is one very important thing I’ve learned through this process: I’d been acting selfish for these past couple of years when it had come to Jude’s friends’ birthday parties.

About once a month, we get an invitation for a birthday party for someone in my son’s class. Ideally, I’d like to be able to go to all of them, but we can’t always make it happen. I think it’s okay when parents can’t make it to a birthday party; we all have our own personal circumstances and it’s not always possible to make it work. There is one thing that’s not acceptable, though: to not RSVP.

Hear me out, I used to be that mom who only nonchalantly RSVP’d once in a while. I didn’t get it. I didn’t understand that my text could make such a big difference. At the birthday parties we’ve been able to attend, there were always at least half the kids’ from Jude’s class. Because there were always so many kiddos, I didn’t realize that my one, single RSVP mattered, but it does.

Only two kids out of twenty-two came to Jude’s birthday party. Two. It was heartbreaking to see Jude the days leading up to the party. I didn’t want him to be surprised/disappointed the day of the party, so I told him that only two of his friends would be coming. He cried and insisted that I was wrong, and that all his friends will come. He even handmade new birthday cards with the idea that maybe his friends didn’t get the first invitation.

In the end, the kids had a great time despite it being a tiny party, but it still left a bitter taste in my mouth. To you, as a parent, it’s just another kid’s birthday party, but to the little boy or little girl celebrating their birthday, it’s a huge highlight and a big deal.

If you genuinely can’t make it, at least take the 30 seconds necessary to RSVP. Just YES or NO. That’s it. If I had known for sure how many people would be coming, we could have turned the party into something better suited for three kids. We could have gone to a fun place. I could have bought the right amount of food and party bags. I could have prepared Jude better. And as a someone who overthinks, I couldn’t help but wonder if we did something wrong. Was it personal? Did I forget to write my number? Did the invitations not make it to the parents? Or was I paying the price for being so scattered brain when RSVPing to other kids’ birthday parties. I’ll never know what may have been for his party, but what I do know is that I’m sorry. I’m sorry that I was that mom who didn’t understand the importance of an RSVP. But I do now.

Your RSVP matters.