Andy Murray admits his success in 2012 has left him hungry for more.
Murray enjoyed a breakthrough season last year when he became the first British male to win a grand slam in 76 years with his success at the US Open, while he was also crowned Olympic champion during a fairytale summer for the Scot.
The world number three is not ready to settle for that, though, and has spoken of his determination to keep on improving and adding to his title collection.
Speaking ahead of the upcoming Australian Open, where the 25-year-old will aim to improve on runners-up finishes in 2010 and 2011, Murray told the Daily Telegraph: "The US Open and the Olympics made me extremely motivated.
"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."
Prior to his success at Flushing Meadows, Murray had won 22 singles titles but had never managed to go all the way in a grand slam tournament, tasting defeat in four finals and reaching numerous semi-finals.
He added: "In the past, there were loads and loads of questions. I wasn't physically strong enough. I wasn't mentally strong enough. Whatever it was, none of that really bothers me any more.
"I'm just looking for ways to keep improving."