As of today, "my five year old" is "my six year old". Six, as any mathematically inclined readers will realise, is one third of eighteen which means that my little fella is thirty three point three three recurring per cent of the way to the age of majority in the UK.
On Thursdays I take him to swimming lessons and Muay Thai classes, which sometimes makes me wonder if I'm not a little paranoid about teaching him to keep himself safe, and that maybe I could have pulled that off just by naming him Sue and lighting out, leaving him an "old guitar and an empty bottle of booze" as keepsakes.
We watch a lot of movies together, bonding - to my delight - over Peter Sellers' Clouseau, "you can walk Chief Inspector, you can walk!"
In a strange way, he reassured me about the educational value of his martial arts lessons the other evening when we were watching "Batman Begins" - the Dark Knight having been redeemed by the casting of a Welshman. Early on in the film Bruce Wayne gets in a big fight in an oriental prison. After being knocked down by the imposing villain he drives back up head first at his assailant's midriff and, while his face is bent down just past his his foe's chest, twists his body and strikes - essentially backwards - with his elbow into the big guy's face.
"That's Muay Thai", my boy remarked casually of this one second detail of the melee and - guess what - he's right. I was mighty impressed.
Happy birthday mate.