I used to find cyclists a real pain in the backside.
They were cheapskates paying no road tax, annoying legitimate road users with their utter contempt for the Highway Code.
I hated being stuck in my car behind some snail-paced, hirsute Guardian-reader wearing one of those ridiculous day-glo jackets that can be seen from the moon with the naked eye.
And God help you if you ever got talking to the bicycle bores, banging on about the planet while getting real ale froth stuck in their beards.
I hadn't owned a bicycle for almost 30 years and had no intention of joining those mugs, getting battered by the elements while I sat warm and dry listening to the radio in my car.
But then I started to notice how a three-mile journey to work in my car could take half an hour because of rush-hour congestion.
Then I realised how much fuel was costing me at a time when environmental worries were starting to prick even my under-developed green conscience.
Exercise was also increasingly difficult to fit into my child-centred evenings, which seemed to consist entirely of taking kids to football, beavers, rainbows, gymnastics and extreme ukulele.
The last straw was when my children, who love going out on their bikes, were mocking me as a petrol-headed dinosaur who couldn't join them on their bicycle trips to the park.
So three weeks ago I bought a bicycle, helmet and lights, and yes, even acquired one of those ridiculous day-glo jackets.
I now commute to work in Cardiff four days a week on my rather stylish mountain bike, a round trip of about six miles.
I know it's not much but I'm getting 30 minutes of exercise on those days that I wouldn't otherwise have had and it only takes me 15 minutes to get to work rather than up to 30 minutes.
Yes, I actually enjoy it and it's doing weird things in other areas of my life.
I was a bloke who referred to children's toys as "landfill" and would think nothing of bunging a California redwood's worth of newspapers into a black bag.
Now, I'm turning into a green fundamentalist, or possibly just a mentalist, who can't bear to throw as much as an apple pip into the rubbish without suffering massive guilt and cold sweats.
As for cycling, I can't pretend it's always an absolute joy, particularly with autumn exacting pleasure by lashing horizontal rain into my face at every opportunity.
I've already fallen off my bike once, cutting my knee and wrecking a perfectly good pair of cords while negotiating a tricky two-inch kerb.
A word of advice. Never mount a kerb at a shallow angle on a bicycle: It will lead to minor cuts and humiliating mocking from workmates.
But for all that, I actually look forward to getting on my bike before and after work and I am feeling fitter with long-lost muscles in my calf slowly appearing.
Those yellow jackets still do look rubbish though.