Yet, it seems to me that those with a family often have more tangible stages punctuating their lives: there's the day they become parents; later, they may become grandparents; and inbetween there are all the defining events that will be remembered and celebrated, such as the one my friend was enjoying so much, the marriage of her child.
Perhaps, in a few years, she will also see the birth of her first grandchild and another chapter of that particular family's life will begin as their lineage continues onward into the future. It's something people like me will never know.
And that - for me, at least - is a jolting part of being childless. However pretentious it may sound, there's the startling fact that my husband and I have severed the thread in our personal ancestry (unless, of course, he should decide to run off with a fertile 20-something).
Despite our respective nephews and nieces taking up the family baton, he and I know that we are not passing anything of ourselves on to future generations.
After an infinite genealogical timeline - impossible to imagine - we have drawn the mark in the sand. Enough. No more. Our bloodline stops here.
What Sharon Parsons is doing here is recognising a good that is not the usual liberal one of autonomy. In fact, she is recognising that she does not exist merely as an autonomous individual, but as part of a family lineage that extends back through countless generations. She finds it startling to be faced with the loss of this lineage "after an infinite genealogical timeline". Ancestral connections do matter to her.
And how did she come to be childless? The usual way for a woman of her generation. She had always wanted to have children:
I always wanted and assumed I'd have a brood of my own. I grew up imagining an idyllic family life and, naturally, I only ever thought about the special times - playing with my children on a sunny beach, seeing them set off on their first day at school, celebrating birthdays and Christmas down the years.
My offspring would - of course! - be beautiful, well-behaved and clever, and would grow up to become happy, well-adjusted and brilliant young adults with fulfilling careers and eventually wonderful children of their own.
But she bought into the idea that a woman's 20s should be devoted to a single girl lifestyle and that family could be deferred until her 30s:
I spent my 20s having a fabulous time and building a career. But I spent my 30s - when I thought babies would surely be the next thing to come along, especially as all my friends were reproducing - slowly coming to terms with the fact motherhood simply wasn't my God-given right.
The deferral of parenthood till some time in your 30s does increase the risk of either not being able to have children or limiting your choice of family size. It would be better for our culture if we shifted back to the idea of marrying and having children, or at least beginning the process, whilst we are still in our 20s.
(To forestall some criticisms here, I do understand that there are people who want to do this but who find it difficult to meet someone, particularly within the current culture of relationships.)