The first time I saw Andy Murray play tennis was at Wimbledon in 2005: he was 18 years old and facing David Nalbandian, who had been a finalist in 2002. Murray was entered as a wild card, and he lost in five sets. I thought, even back then, that there was something interesting about him. Yes, he was gangly and awkward but he snapped those backhands over the net with more than a hint of promise. He also had what every mum in the country loves – a committed, passionate, ambitious mother.

True, he was Scottish, not English like Tim Henman, and we Home County types quickly labelled him a "dour Scot" – not stereotyping or anything – but we were prepared to overlook that because he could seriously play tennis.

Murray then went on to upset virtually every English person by saying he would support "anyone but England" in the 2006 World Cup and his reputation as a dour Scot was sealed. Except, of course, none of us realised that it was a joke.

Over the years, I have been seduced by Murray. I love his commitment, his power, the way he is such an open book on court. He doesn't have the European elan of Federer or the wildness of Nadal. But surely only the daftest amongst us could describe Murray, with his grimaces, frowns, sighs, smile and – OK, occasional – laughs, as dour now.

He is brave and he is driven. He has bulked himself up over the years so that now he is that rare physical specimen – a true athlete. Where those daft few see dourness in him, I think they are really reacting to his single-minded pursuit of being the best he can be. He has that Scottish Presbyterian work ethic. He doesn't just want to get in to the Wimbledon final. That's not enough for him. He is desperate to win it.

And I, for one, love his downbeat persona off the court. He's not showy. He doesn't do celebrity events. He rarely does interviews and when he does, he doesn't mince his words. When asked how he though his family felt during the semi-final he basically said, "I don't know. It's a lot tougher for me." I thought that was genuinely very funny and refreshingly honest. Not dour in the least. Really.