On the day before Mothering Sunday I got up early and drove alone to Birmingham to put flowers on my mother’s and my grandmother’s graves, a timeless act of ancestor worship. Two years ago, when I took my then three-year-old son with me, he accidentally flung a 2ft-long branch into the door panel of a passing hearse. The resounding clang made the passengers inside it, and the followers in the rest of the funeral cortege, scowl and stare at both of us in anger and shock. Safari park aerial-snapping apes had nothing on us, the monkey-man and his cub, making futile war upon the newly dead.

Now time has passed, I hope the incident is remembered by the relatives as an amusing family anecdote, rather than the final indignity in the wretched carnival of endless misery and systematic humiliation we laughably call someone’s life. The Co-operative Funeralcare website is diplomatically disappointed in the lack of respect shown to funeral corteges nowadays, conceding “the pace and pressures of life have increased”, but does not include “attack by tree-wielding child” in the list of insensitive hazards mourners may face.

Last weekend one of the graves bore a picture of the Virgin Mary alongside the fresh flowers, I assume in respect of Mothering Sunday. Christianity has efficiently co-opted keynotes of earlier faiths (the God reborn in spring, the God born of human woman, and the conflation of Mary with various pre-Christian mother goddesses) and it certainly has more in common with the pagan religions it assimilated than, for example, the current lineup of the Sugababes does with the classic 1998 Mutya-centric lineup. I wouldn’t normally have made the Mary-mother goddess link, but I had this column hanging over me, and was desperately on the lookout for random event linkage, assumed meanings, and funny paragraph endings, the third of these proving especially elusive.

On Mother’s Day, we went to see the Ice Age Art exhibition at the British Museum. The oldest piece of identifiable human art ever made turned out to be a tiny sculpture of a pregnant woman. Conveniently for me, with the deadline for this column approaching, it appeared that pregnant women were the main concern of ice age artists, although, about 40,000 years ago, some visionary goofball did come up with the idea of putting a lion’s head on a man’s body. As the exhibition notes explain, the so-called Lion Man of Hohlenstein-Stadel is the first example of the human mind imagining something that didn’t exist. “Assuming,” my wife countered, “that there wasn’t a man in the Hohlenstein-Stadel area struggling through life with the head of a lion.” Women say the funniest things.

But the lion man was a blip, presumably greeted by acres of tablet outrage akin to the Sex Pistols’ Grundy interview, and the lion-headed man disappeared from human consciousness until his re-emergence in 1985 in the form of Lion-O from Thundercats. The ice-age artists swiftly returned to the more acceptable business of making more and more pregnant women. Everybody loves mothers.

My favourite mother goddess survivals are Sheela na gigs, the courageously obscene female carvings brazenly cracking their crannies in rural church nooks. A few years ago, when I was walking on Long Mynd in Shropshire, I popped into the church in Church Stretton to seek out the especially pungent Sheela reputed to reside there. “Can I help you?” asked the priest suspiciously, finding me staring at the roof like someone planning on stealing it. I decided to come clean. “Yes reverend,” I said, biting the bullet, “I am looking for your obscene fertility goddess. I know you’ve got one. Now where have you hidden her?” Needless to say, he was delighted. Everybody loves mothers.

The priest took me outside to point out a haunting and all but eroded figure above a now bricked-up entrance, her legs wide open to the north wind. “In the old days people liked their coffins to enter the church through this doorway,” he said, “and that way the dead got the blessing of the new God, and perhaps the blessing of the old goddess too.” The doorway was Norman, so this ancient mother-worship had survived in secret, in the fabric of this particular Shropshire church, until at least the 12th century, despite efforts to move the celebrants towards a more dignified substitute. Looking closer, I noticed the Sheela’s own little doorway had been plugged too, and rather indecorously, probably by a late Victorian, with a single and censorious stone. Shame. I thought everybody loved mothers.

In the 1990s, the comedian Simon Munnery had a joke that ran: “Everybody loves nature. Except when it’s growing out of cups.” I used to hear it as the self-justifying statement of a typically hygiene-averse intellectual, such as the young Simon himself, using philosophy to justify his dirty crockery to disgusted visitors, such as me. But, like many of his gags, now it seems to have a deeper dimension, reflecting how any aesthetic or moral values we see in nature have been put there by us in the act of observing.

To paraphrase Simon, everybody loves mothers, as long as they restrict their fertility to the outlines demarked by the social and moral norms of the age they find themselves in, and don’t have the audacity to give birth too young, or too old, or too regularly, or at too great a cost to the state, or to a child that they share with another parent of the wrong race or gender. Like mould in a mug, nature itself just is. Natural processes just are. The attribution of values is exactly the sort of lion’s head on man’s body move that makes us the brilliantly deluded creatures we are.

The cemetery had been busier than usual the day before Mothering Sunday. And if I hadn’t bought my ice-age art tickets in advance we wouldn’t have got into the show the next day. Last week, it seemed to me there were mothers everywhere, and that some unseen force was organising events in my life into the shape of the newspaper column I was contracted to provide. Either that or, like ice-age man, I was slipping back into a bicameral state, and hearing my own thoughts as if they were the voices of spirits. There’s a contrivance about dividing yourself into observer and protagonist in order to fill column inches. I don’t know if I’m cut out for it. Does Dom Joly have this problem? Who wrote this? Am I … am I God?

Stewart Lee is currently curating The Alternative Comedy Experience on Comedy Central, Tuesdays at 11pm David Mitchell is away.