This has been a frequent question in our house lately, now that Sam is suddenly interested in letters and numbers: “How do you spell mama?” “What is 5 and 5?” “How do you make 13?”

Easy answers.

But today is our 13th anniversary and suddenly, I am not sure how one makes 13. It’s not just a matter of simply writing one number after the other — is it?

I spent the morning sending my husband calendar appointments for various trips and plans that I have so that he can take all of that into consideration when he makes his travel plans for work. It all seems very official and clinical, like we are running a business together.

Before you get married, or even when you are first married, you do not think of your relationship in cold business terms. And I still don’t — but somehow it’s all necessary. The listening, the scheduling, the planning, the changing plans to accommodate the other. It is not sexy at all. It is the opposite of sexy.

But maybe our idea of what sexy is changes over time. I used to yearn for flowers and cute cards and jewelry for our first couple of anniversaries. Now I just want us all to be at home at a reasonable time in the evening so that we can eat burgers and drink champagne — a tradition left over from our first anniversary. I want our calendars to synch up, so that we don’t miss anything. I want the easy shorthand of our relationship. I want simple, I want boring, I want predictable.

I know that we are supposed to keep our marriage fresh and spice things up with date nights and lingerie and new adventures together. Am I the only one who is too exhausted to do that? I am busy putting one number in front of the other. I want a comfy bra and my yoga pants. And wine.

Spice, to me, comes from security. From knowing where my next kiss will come from. That I will be making dinner and a pair of strong arms will hug be from behind and just stay there for a few seconds. That I can take up the entire couch with my laptop and notebooks and that around 10:30 I will get a gentle nudge to go to bed.

Or that I can put 1 and 3 together and somehow make 13.