MELBOURNE, Jan 11 (Reuters) - Achieving a lifetime goal can leave some players content but may also blight their ambition. For Andy Murray, however, nothing could be further from the truth.
The Scot's victory at the U.S. Open last September came on the back of his Olympic triumph the previous month and was the fulfilment of a dream.
But with the new calm that success brings showing in his improved demeanour on court, the 25-year-old is more determined than ever to add more grand slam titles to his tally, starting at the Australian Open, which begins in Melbourne on Monday.
"The U.S. Open and the Olympics made me extremely motivated," Murray told reporters this week. "It wasn't a case of 'Oh, everything's done now'.
"It's taken a long time to get there and to win those sorts of events. I know the feeling when you do win them now and it's worth all of the work that you put in.
"In the past, there were loads and loads of questions. I wasn't physically strong enough. I wasn't mentally strong enough. I didn't listen to my coaches. I was spoilt.
"Whatever it was, none of that really bothers me anymore. I'm just looking for ways to keep improving."
The next chapter begins on Monday when Murray bids to become the first man in the Open era to follow up his first grand slam title by winning the very next one.
It is a difficult task; Pete Sampras, who went on to win 14, took 11 grand slam events to win his second title, while Novak Djokovic, the man Murray beat to win in New York, took 12 more slams to win another one.
Murray picked up where he left off in 2012 by winning his first event of this year in Brisbane and will go into Melbourne as the second favourite for the title behind Djokovic.
In the past 12 months, Murray has transformed himself from the nearly man of tennis into a national hero.
When he lost to Roger Federer in the final at Wimbledon last summer, his fourth defeat in grand slam finals, the knives were out.
Critics claimed that Murray had missed his window of opportunity, that as he entered the second half of his twenties, his powers would begin to wane.
But when he struggled to hold back the tears in an emotional runners-up speech at Wimbledon, the effect was to bring the public on his side, perhaps more than winning the title would have done.
And when the Olympics came round at the same venue just a few weeks later, he produced inspired tennis to beat Djokovic in the semi-finals and then wipe Federer off the court in the final.
The foundations had been laid and he maintained his form and focus in New York to beat Djokovic and become the first British man to win a grand slam singles title for 76 years.
"I was motivated to get back into the gym and get even stronger," Murray said a week after his U.S. Open victory.
The Australian Open represents the anniversary of his partnership with Ivan Lendl as coach, a relationship many feel was the key to getting Murray over the line.
Darren Cahill, a respected coach and television pundit with ESPN, says the former world number one has had a huge impact on Murray.
"They're 12 months down the road now, they have an Olympic gold medal under their belt, a U.S. Open under their belt and I see a little bit more swagger on the court," said Cahill, who has worked with Murray in the past.
"It doesn't mean anything when it comes to playing these top guys. (But) it means he's not focusing on that one major, he's focusing now on multiple. There's no question he's capable of winning multiple slams."
After his win in New York, Murray said he was happy that he would no longer have to answer questions about Britain's wait for a grand slam champion.
A semi-final effort in the ATP World Tour Finals was a solid if unspectacular performance but his focus is very much on winning grand slams and edging towards his goal of becoming the world number one.
With Djokovic looking strong at the top, that may be a little way off still but now he knows he can do it, Murray is hungry for more.
"Who knows how much that win at the U.S. Open is going to help Andy in the big situations?" Cahill said.
"This is the first time Andy has ever walked into a major championship as a major winner, as a grand slam winner. Who knows how much confidence that will give him?" (Editing by John O'Brien)