Why do women who are childless by circumstance feel compelled to take the road less travelled?

If you’re one of the unfortunate women trying to buy Cystopurin today, you’ve probably discovered by now that your local pharmacy is out of stock.

Why, you might ask? Because yesterday was National Baby-Making Day — the annual festival of bonking that bookends the festive season with a literal, and figurative, bang.

According to fertility experts, couples are most likely to conceive on the second of January because many of them are trying for a September baby, which could give the child an educational advantage.

Good luck and Godspeed to those who tried to pull off this feat, but let’s not forget that conception may not occur with clockwork precision.

Those in the game a little longer know that the biological clock doesn’t always chime with reproductive certainty, just as they know that infertility can be both a medical and social condition.

To put it more plainly, some women can’t get pregnant with their partner and some women can’t find the right partner with whom to get pregnant.

Social infertility is a widespread phenomenon but it remains something of a hidden demographic. There are considerably more childless-bycircumstance women than there are childlessby-choice women, yet the experiences of the latter group tend to overshadow the narrative.

Besides, those experiencing social infertility tend to keep it to themselves. Unless of course they’re in the public eye, in which case they are portrayed as having a ferocious reproductive idée fixe.

Take, for example, TV3 presenter Elaine Crowley (pictured), who has in recent years become an unwitting spokeswoman for this group. You would be forgiven for thinking that the Corkwoman only does interviews with the press to discuss the tick-tock of her biological clock and her diminishing ovarian reserve, but it’s important to note that journalists hone in on this line of questioning when the female subject is single, over the age of 35 and, presumably, weeping into a goblet of Beaujolais.

Anyway, Crowley, who turned 40 in August, was once again asked about her personal life in a recent newspaper interview. And, as always, she was frank and forthright.

“I do wonder how different my life would be if I was married and had kids of my own,” she said. “I thought it would have happened by now and it hasn’t. I think that ship has sailed.

“My hormones are flying off the cliff. I know I can physically and medically still have kids of my own but it’s very unlikely now. I am resigned to the fact.”

Crowley’s words will no doubt resonate with those experiencing circumstantial infertility, just as her plans for 2018 will probably sound familiar. She wants to visit South America and, eventually, Antarctica. “I am very impulsive,” she added. “I have been known to fly off to Thailand at the drop of the hat from time to time.”

There is no question that Crowley is an enthusiastic globetrotter but why are childless people — whether by choice or circumstance — compelled to book so many last-minute, off-the-beaten track holidays?

Why do they always mention their ability to “take off to Paris tomorrow”, as Noah Baumbach brilliantly observed in his film While We’re Young?

Is it a simple case of having more time and money on their side, or do they feel under pressure to do something remarkable and meaningful with a chapter of their life that they thought would read differently?

Do they see their friends ticking off the milestones of marriage and babies and decide that they’ll carve out their own life journey through passport stamps and continents?

After all, the more Lonely Planet books you own, the less lonely you are, right? Right?

There is an infertility grieving process, but we generally only recognise it in those who are actively trying for a child.

Conversely, those who never got the chance to try aren’t given an outlet to grieve for what might have been.

Instead, they are given a couple of ready-made identities to step into, and most would prefer to be thought of as a spontaneous globetrotter than — perish the thought — a crazy cat lady.

Sure, nobody has ever regretted a month in Sri Lanka but it’s worth thinking of the pressure the socially infertile are under to thrive rather than just survive.

Perhaps it’s time we started to spare a thought for these intrepid travellers — after all, they are on a braver journey than we might realise.