I have long held the belief that the concept of the terrible twos is a complete and total scam that serves to brace us for the insanity that follows: THREE.

Three has been a tough year around here and, last night, we said farewell to it for the last time. Today, my youngest is four. And, look, I don’t have any delusions of grandeur that ushering in the age of four will flip a switch and deliver us a consistently flexible and mellow child. But I like four, even if it means he is less of a baby (let’s pretend that’s not true).

This year saw him change in endless ways, from making friendships of his own to chatting up any stranger at all, in any location. If you were on the receiving end of such an exchange — perhaps in Target, the grocery store or just strolling by our front yard on a leisurely walk — I’m pretty sure you received the entire history of our family, and maybe my Social Security number as well. Sorry about that. But it’s nice to see that his initial speech delay seems to be a distant memory.

In other four year-old news, I hate to admit that it seems Thomas and the Island of Sodor may be on their way out around here, after a solid ten-year run and seemingly endless dollars spent on their expanding merchandise inventory and horrible movies. I’ll miss you Percy and Gordon, and I hope you’ll listen to me when I say it’s time to rise up in a magnificent rebellion to fire Sir Topham Hatt once and for all. His management style is outdated and brash, at best. Direct him to collect his railway pension and be on his fucking way already. And don’t let anyone tell you you’re not useful engines.

Where Thomas may be fading away, my resident birthday boy will NOT be pushing Lightning McQueen out the door anytime soon. In fact, he pretty much thinks the upcoming Cars 3 film was made specifically for his birthday, and I may move into a white room with padded walls soon if we have to watch the trailer on YouTube one more time. I also want to go on the record as saying that the laws of stalking a fictitious character are pretty ambiguous, so I think my son has dodged any legal trouble. For now.

This child has also taught us that, when you have siblings who are six and four years older than you, you pick up a lot of things that maybe your parents weren’t anticipating. Ever eager to be in the mix with the older kids, it’s amazing to me how he can adapt to their interests and, uh, verbal choices. I’m starting to think his only friends in life will be others who are the youngest in their families as well.

In between his frenetic quest to keep up and grow up, I still hear plenty of “I just want Mommy,” or “I need you to pick me up.” He still lets me sit in the glider with him most nights and sing songs while his head rests in the same crook of my neck. And, many times, when we are alone in his chair with just a night light and sound machine on, there is something I think about.

I think about when I sat in a high-risk obstetrician’s office in 2013, because I was beyond advanced maternal age, pregnant at 40 (yes, on purpose). And in that position, you expect to hear a lot about the increased risks of delivering a child in what some people acted like was an outright geriatric state.

“Unfortunately, we are looking at one in twelve,” the doctor said to me.

I blinked a few times, as if my eyes would adjust my hearing.

“One in 12,000, you mean? Or one in 1,200?”

“One in twelve,” he repeated. “Those are the odds of this child having significant chromosomal abnormalities based on our testing.”

For my oldest child, six years earlier, those odds had been 1 in 36,000. Now, I was looking at one in twelve. One in twelve. One in twelve. One in twelve. It was all I could hear.

When I became pregnant with my third child at 40, I was all in for all of the pre-natal testing that I could get my hands on. Not because the results would change our decision to proceed with a pregnancy, but because I wanted every avenue possible to minimize potential medical surprises in the delivery room. If my child was going to be born with a chromosomal abnormality — be it Down Syndrome or another — I wanted to know in advance and prepare — mentally, financially and otherwise.

A nurse appeared with some tissues, and a genetic counselor also found her way in to sit down with us. I didn’t know genetic counselors existed and this stranger was assigned to talk me off of a ledge.

“For more serious abnormalities — ones that typically result in death upon or shortly after delivery — those odds are one in 36 for your child.”

I could not breathe.

I imagined a line of twelve children lined up. Or 36 children. One would be dealt a life-changing diagnosis. Would it be mine? Would my child be the one? It was unfathomable.

I like to gamble. Recreationally, that is. I don’t sit home and bet on fights or on the weather. But show me a roulette table and I can spend a few hours hanging out with a little cash, idly trying to defy the worst odds in the house while waiting for my beloved favorite numbers to come up. I never really minded the terrible odds of the little spinning ball in the wheel because I never have had that much riding on its outcome.

Real life odds are another matter entirely. And, when staring you in the eye, they can consume you. And I beat myself up endlessly, convinced I had been selfish to push my luck and have a third child at 40, when I already had a perfectly healthy boy and girl. Maybe it doesn’t sound sensible, but fear breeds all kinds of crazy.

I waited two agonizing days to get definitive results back, during which time I mentally role played both possible outcomes in my head millions of times. I was not prepared for the third outcome, which was an extremely apologetic OB on the phone saying the sample they got was not sufficient and we needed to come back in and REPEAT THE TEST. So it had to be re-done, and we had to re-wait for two additional agonizing days. And when I got the call that the test was negative for any abnormality, I was so light-headed that I only realized in that moment just how much I had been bracing myself for life-changing news. The doctors still felt there may be a reason for the initial flags, and so there were other areas to test — cardiac, more genetic possibilities, and others — one by one, like hurdles that were individually cleared well into my sixth month of pregnancy. When there were no tests left to do and no answers about what caused the initial scary results, my OB said it was “very likely” an inaccuracy, but there was still a 10% chance something else we couldn’t test for would present itself after delivery.

But when he arrived, evicted by induction, just like my other two stubborn children, he was perfect. And to be clear, I didn’t need for him to be perfect. I don’t doubt for a minute that children born with some of these conditions I feared live very rich, long and wonderful lives. But the fear of the unknown can be a beast. And I make it a point to remember those times as often as I can when I hold this sweet child in his chair at bedtime.

And now he’s four.

I am admittedly bad at being present, feeling grateful and recognizing all of the good around me. I have a mind that reels around its to-do list and a pretty cynical view of things. But those days of testing, of waiting for results, of preparing for an unknown outcome stay with me.

My youngest isn’t really a baby anymore, but he must know by now that I’ll probably refer to him as one forever. I challenge you to find him without a car in his hand or a pretend story coming out of his mouth, gesturing wildly as if he’s a jaded man in his 70s, wise beyond his years, mumbling “Unbelievable” when things don’t go his way. He wants so much to be big and know what his siblings know, but he’ll crawl into my bed in the morning and insist without words on a full-body hug in his footie pajamas, hoping it will be a pancake day.

The threes weren’t always easy, and yet sometimes they were the sweetest thing in the world. I can’t wait to see what four looks like on this child.

Happy birthday to my sweet, sweet baby.