Ewan Morrison: I'm going to kill off the Calvinist within, even if it means taking out Marx with him

DRIVING south from Inverness with my girlfriend and the kids, and the white peaks of the Cairngorms rose triumphantly ahead, gleaming in the sun as we all sang along with Julie Andrews: "Doh, a deer, a female deer, Ray, a drop of golden sun." I found myself smiling, telling myself: "Yes, I've never been happier."

It didn't last long. The inner voice started: "You may think you are happy now, but one day your kids will grow up and leave you and you will die alone."

A chill passed through me as it droned on. "Most people live lives of abject misery. You have no right to be happy – how dare you be so selfish."

I turned off Julie Andrews before the chorus, chastened myself and stared out at the road in silence, while the kids complained bitterly that I'd spoiled their fun.

The voice in my head was the old grey man. The one from the statues, with the great black book and the 'ism'. Mr Calvin. As I get older I'm increasingly aware of how long a shadow his corpse has cast over my culture. How, at every turn, he's waiting to remind me that my glass is not half full but half empty, that if the sun is shining today, it will rain tomorrow. Dourness, negativity – call these traits of national character, of Scottish temperament, but I am sick to death with them.

Life is short and I should like to be able to be happy without guilt, for just a few minutes.

That I'm plagued by Calvinist guilt is a real shock to me. Although my grandmother was a stern bible-bashing, tartan-clad miserablist, my parents were hippies and spent a good deal of effort (when not partying) decrying the nay-saying of the cold grey church.

The only Calvin I have anything to do with these days is a cartoon character with a cat-friend called Hobbes, and the underwear that clings to my bum.

So why then does his grey ghost of guilt haunt me? Why can't I let myself be happy? I'm no historian but it seems to me that Calvin lives on in the attitudes of the other great nay-sayers of Scotland, of which I was once a proud member: the socialists.

I've heard it said among the Scottish left that, out of respect for the downtrodden, we should not be exuberant or celebratory. That there can be no real happiness till the problems of the oppressed have been resolved. That to be happy now is reactionary, bourgeoisie and decadent – in fact, almost evil. The meek shall inherit the earth, come the revolution – or at least the next election.

These left-wing beliefs start to sound just like Calvinism when we accept that, since the problems of the under-classes are immense and may never be resolved in any meaningful way (and since there is no empirical way to measure the happiness of the masses anyway), this gives us a life-long obligation to be unhappy.

To hell with it. I'm going to kill off the Calvinist within, even if it means taking out Marx with him. No more self-imposed suffering for the sake of the masses or God or anyone. No more asking anyone else's permission to smile.

I'm going to make an effort to allow myself to be happy – stupidly, innocently happy, even if it means renouncing the great virtuous misery us Scots hold so dear.

Let the hills be alive with The Sound Of Music.