Dear Kids,

There’s a story behind the candles on my cake tonight. Lopsided, mismatched, but clearly spelling out my age–41–even though I can barely believe I’m older than 25. Where did the time go?

It was your nanny, Patricia, who frosted the chocolate cake today and fished the numbered candles out of the box that holds the birthday stuff: cute gift bags, rumpled tissue paper, a package of smashed bows. I have this box now because I have you two–because you two are invited to a parade of birthday parties that require me to wrap presents at the drop of a hat on any given weekend.

Of course I didn’t wrap my own presents today. Your dad did that, with lots of “helping” from you guys. It was fun to see your faces, expectant and waiting, as I ripped into the paper to open my gifts.

I never knew if I was going to have children. My mom, your Grandma Sheri who you never met, had her children later in life, so it felt like I had plenty of time. As it turns out, I had kids even later than she did, squeaking the second of you out as the sun set on my 30s.

In other eras of human history, 41 would have been a ridiculous age to have a five-year-old and a two-year-old. But in this era it feels just right: I still have enough energy to hoist you onto my hip while cooking a stir-fry with one hand, but I’m old enough not to take myself too seriously, to realize that everything is going to work out just fine, even when a crayon gets swallowed or someone eats nothing but lychees for dinner (I’m looking at you, L).

Back to the candles. I recognized the “1” immediately. It was part of a multi-pack I bought last year in Mauritius at a shop stuffed with all manner of cheap toys and random things like clear plastic shoes for wading in the ocean and glittery shirts for five bucks that you could wear to go clubbing. We were in Mauritius because I was much more rattled by last year’s birthday than by this one and had to haul our entire family to a tropical island as a coping mechanism as the decade turned. It was an excellent distraction.

But the airline lost our luggage, so on the first full day of our vacation, your dad and I took a taxi to buy clothes for my birthday dinner and bathing suits for you two who were clamoring for the beach. Mauritius is almost as much Indian as it is African, so we ended up buying shalwar kameeze instead of Western clothes. Putting on the long, flowing, elegant cloth–which is both more fabric than we’re used to and yet somehow lighter and less–felt like coming home. It reminded your dad and me of our days in Pakistan, where we wore shalwar every day, where we met and fell in love, where we tried to make a difference, where we never talked about having kids but worked really long hours instead.

Across the street from the clothing store was the shop that sold everything; we snagged SIM cards for our phones, sunscreen, a pink backpack with a monkey on it. Just as we were about to ring up, a glass case crammed full of supplies caught my eye. Clearly this was the party shelf: Mardi Gras masks, complete My Little Pony or Monsters Inc sets with napkins and hats, shiny kazoos, and birthday candles.

I love candles on a cake. I love the moment the cake comes out: everyone singing and faces glowing in the soft, happy candlelight. I don’t care if the cake is lovingly homemade or a stale piece of something brought out by a restaurant kitchen, but I want a candle to blow out when the song is done, to make a wish on for the next year.

So I rescued the crinkled pack out of its dusty spot and gave the “4” and the “0” to the hotel staff in advance of my birthday dinner with clear instructions about placement. (I’m not afraid to orchestrate my own momentous occasions, as you must know by now.) At the end of the vacation, the rest of the tiny waxy numbers got taken home in our recovered suitcases, stuffed next to parrot tee shirts from the resort kids’ club and a monstrous box of Oreos from duty-free.

KonMari method notwithstanding, I don’t throw much away. You never know when you’ll need spare birthday candles, or have to throw an impromptu party, rustle up a small gift, or in some other way shepherd along a celebration.

For the “4” on tonight’s cake we have to go farther back in time. Years before I could even imagine the two of you, I packed my bags to embark on a new life and job in Islamabad. I couldn’t imagine what was awaiting me, but I prepared myself against the unknown with a final, wild veer through America’s retailers stocking up on what I might need. I bought my favorite face moisturizer, cake mixes and taco seasoning, fluoride-free toothpaste and a karaoke machine. I also bought two super foofy eco candles dyed with nothing but beet juice and corn husks at Whole Foods for an exorbitant price. You know the type. I bought “3” and “4” in preparation for my next birthday that was still months away.

But I ended up celebrating my 34th in Michigan with my family on summer vacation, so the candles stayed stowed. After a couple more years they traveled across two oceans by ship, moldered in a storage facility in Washington DC, and then hit the high seas again when we moved to Africa, just waiting to be discovered by Patricia and put to use tonight. Well, one was waiting at least. I have no idea what happened to the “3,” just like I have no idea what happened to my 30s in general and how they could have slipped away so quickly.

How can I explain to you how fast the time goes? I guess I don’t want to. Part of the gift of youth is not understanding how soon it will pass. It’s a beautiful luxury not to consider old age or your inevitable death, or at least to consider it rarely. When your life inches near the halfway point, those thoughts loom a little closer.

But now I have the two of you to keep me young, to push up the volume in the house to full energy, to dance after dinner to Lady Gaga or to whip and nae nae around the living room together. Just as it has been every year since I became a mom, you are my best birthday present. I am so lucky to have you both.

The truth is we’re lucky to have each other. My own mother was 41 when she found out she had cancer, when she realized the life she had with her young family might not turn out the way she had expected. By that age she had less than three years to live, but of course we didn’t know that at the time. I don’t remember how we celebrated her birthday that year, but I hope it was a joyous and happy day. I’m sure there was a cake with candles.

From here on out, I know it will continue to be a wild ride. It’s clear to me now, at age 41, that you can’t plan anything, not really. The items you squirrel away for one purpose get used for something else entirely, or not at all. Those things you wanted so badly, the person you thought you were: this changes sometimes in the most surprising ways. The careful preparation, the shoring up against trouble, the plans you make to protect yourself and your loved ones: they don’t always work, and you will see more people around you struck by tragedy, heartbreak, and disappointment with each year that passes.

So the candles are important, wherever you can find them. From the spark of the flame touching each wick, to the wisps of smoke lingering after they go dark: it is a ritual of hope. We don’t know what the next year will hold, but we can still make a wish, faces lit with the rosy glow of hope and expectation, ringed around together rooting for the same things. We celebrate when we can, and we do it together: that is the important part. I hope I am teaching you this every day, and that you won’t have to wait until age 41 to find out how important it is just to be, not to prepare–just to hope, not to fear. I am still learning too. I love you guys.