And after clearing his summer schedule last month by finally qualifying as a doctor from Cardiff University - and with it banishing the hours of dedicated studying - Roberts has only one thing on his mind.
The 26-year-old centre was a key member of the previous 2009 Lions tour to South Africa, picking up the player of the series accolade, and he admits the magic has not worn off second time around.
"I haven't been more excited for a tour in my life. It's such a magical thing," said Roberts, who is a British & Irish Lion and HSBC spokesman.
"South Africa was an amazing experience to get a chance to tour that country.
"But I think Australia with its sporting heritage; it's going to be a fantastic country to tour.
"The Lions is the ultimate; it's the pinnacle for rugby players' careers."
Up against countryman Jonathan Davies and fellow centres Brian O'Driscoll and Manu Tuilagi, the Welshman will be pushing hard for a place in the starting line up for the series opener in Brisbane on June 22.
But despite the battle, he insisted any individual goals would be outweighed by the collective target of a series win.
"The talent in the centre is pretty special," he said. "The competition for places is pretty intense.
"But there are no individual goals so to speak. You don't go out with the aim to achieve player of the series.
"If it happens it happens. I picked up that accolade in 2009 as part of a very strong team.
"But it's about taking each match as it comes. The aim is to go and win."
Meanwhile, Roberts could be forgiven for letting thoughts drift to his impending move to French side Racing Metro next season after an entire career spent with Cardiff Blues.
But despite reaching a crossroads in his life, the focused player insisted any relocation issues would be waiting until his return from Australia with the Lions.
"For me, I have had 26 years in Cardiff, it is time to fly the nest and try something new," he said.
"I'm just going to be a free spirit for a year or two. It's a new group of people and teammates and I've got a make an impression as well. So that's a challenge in itself.
"The Lions is first though so anything like house-hunting and moving will be done afterwards."