People say "Oh, you never stop worrying about them!".

Back when Sim was newborn, it barely seemed conceivable to me that I could worry as much about him as I did then- surely 20+ years of that kind of adrenaline-fuelled, well, edge of panic, for want of a better description, would see one safely into the grave before well said child reached adulthood?

Fast forward to toddlerhood and the seemingly endless trips to A&E, the seemingly unending death wish of my son, the seeming relish with which he attempted the thing most likely to injure him (successfully quite a lot of the time), fast-forward past the madcap tree-climbing, the rock-scrambling, the crazy expeditions avec enfants led by the Boff who behind a mild and unassuming scientist exterior, hides a core of utter unthinking recklessness*, fast forward past the only slightly potentially lethal Ten Tors expeditions and RAF cadet flying sorties, fast forward past all of these things and we are here: Sim at 18, setting out into the world on his own.

So Sim flew a few days ago to Spain, with Dill, who at just 14 (the previous day) is old enough to travel unaccompanied on the orange budget airline but not old enough to act as chaperone to our borrowed Spanish child. The plan for Sim was that he would walk/trek/take the train back slowly through Spain and southern France, before arriving at his grandfather's in northern France in about ten days' time.

My father was to have taken Sim on a tour of the Loire valley grandes caves castles. As turns out, my father is unexpectedly in hospital, very ill with peripheral vascular disease in his lower legs (about to lose a toe and undergo a leg bypass in fact- I guess the 30 units a day for the last 40 years is starting to catch up with him at 72).

Sim's increasingly mournful texts and emails over the last few days show that he is really slightly at sea on his own. Having set off with high ambitions and very little preparation, he is now faced with the reality of being on his own far from home and with little comfort and he is not embracing the concept. Far from relishing being Down and Out in Paris and London, he is Taking Trains North as Quickly as Possible, to rejoin granny's home cooking a bed.

I can't say I'm not slightly disappointed. Not in him, but in my failure to adequately teach and encourage him to seek out the world rather than seek to avoid it.

It is, I imagine, just one of many instances in his life as young adult where I have to watch him fall and have no graze to mop. It is perversely harder than 16 years ago. It turns out those people were right- you don't ever stop worrying about them. You just have less and less of a role- the worry goes underground by degrees.