I THINK if one thing would improve the quality of my life, it would be to develop the ability to assess accurately how good I will be at a particular task.

“Oh, yes,” I find myself saying far too often. “I am a grown man. I shouldn’t find that bulky object too difficult to carry.” Or I say, “Hmm, I walk fairly quickly, and I am well acquainted with the timetables of local public transportation. It will probably only take me half an hour to get to this place.”

And then I end up late, covered in sweat and soil, staggering under a bulky object, incapable of chewing the amount of stuff I have bitten off.

“Know your limits, Bainbridge,” I forever tell myself, while also seriously overestimating my limits. Which is how I found myself limping through the city centre.

An old friend had complained about her inability to assemble a flat pack bed, which had rendered her sofa-bound. And I volunteered to help. It is not for me to call myself a hero and/or saint. Indeed, if you did call me that – and you should – I would dismiss the suggestion.

I am a competent flat pack furniture assembler. This always comes as a surprise to people. It is as if Kenneth Clarke MP had disclosed that he was a dab hand at pole dancing. But it should not. I am a plodder who needs instructions to do anything correctly. And flat pack furniture comes with instructions.

I put together an entire wardrobe in two and a half hours. The last time I assembled a bed it took me two hours. This bed seemed slightly more complicated, so I estimated it would take me another hour. But seriously, how difficult could it be? It was a bed. Beds aren’t tricky. They have four corners and a mattress. They don’t have engines or wi-fi or opinions.

I arrived at my friend’s flat with a screwdriver set and hammer, and my phone pointing at the series of texts with my friend outlining my intent to assemble a bed in case a police officer arrested me for “going equipped”. I do not think I carry myself like an opportunistic burglar, but you never know.

It became quickly apparent that my three-hour assessment was miserably off target. It took me 25 minutes to open and dispose of the first box. It was an hour before I had put in the first screw. And the instruction booklet was longer than some novellas.

It was an Ottoman bed, named after the bloodthirsty empire, presumably, which involved springs and hinges and – according to a calculation I have just done using the assembly instructions available online – 90 individual screws.

That’s 90 screws to be fixed with my terrible Phillips screwdriver and one of three Allen keys. And roughly 60 of those screws had to be affixed at floor level, which involved me crouching like Gollum, only a Gollum who, instead of punctuating sentences with “my preciousss”, constantly swore at slipping Allen keys.

But on I pressed, like the hero/saint I refuse to let you call me, until, finally, we came to attach what I am going to call the insanely complicated mattress-holder thingy (ICMHT) to the spring-loaded hinges. There were no holes through which I was supposed to push the screws.

I realised at that point that my limits also include the inability to distinguish left from right. For some cruel reason, the ICMHT could be convincingly constructed the wrong way round.

I wept and undid the 45 minutes it had taken me to construct the ICMHT and rebuilt it correctly, so the holes would be at the right end. Then we attached it to the hinges.

Then we pushed it down into place, and it sprang back up. We did this a few more times until I realised that my limits also include the inability to distinguish up from down. For some cruel reason, the ICMHT could be constructed the wrong way round AND upside down.

I wept and undid, etc, etc, until finally the ICMHT was in place, fully slatted, with a mattress resting upon it, SIX hours after I had ripped open the first box.

And five hours of affixing screws in a crouching position have left me unable to stand or sit without complaint, and walking like an elderly nun, dragging a ball and chain, who is in no hurry. It has not improved the quality of my life one bit.