The Team Sky rider was one of the revelations of this year's Tour; he was the E3-Harelbeke champion and burgeoning one-day star up there in the top five on GC for much of the three-week race. Riding as right-hand man to overall winner Chris Froome, Thomas eventually fell away on stage 19 but the experience nevertheless told him that the overall is a tangible prospect for the future.
"I certainly think it's a lot more achievable than I did three months ago," Thomas said in an interview with The Guardian. "If I keep on improving, commit to it totally, have a team around me, a podium is certainly realistic. And you'd aim to win it. You would be there or thereabouts – especially if the route was good for me. It's certainly exciting."
Of course, it's hard to see Thomas having the space for a genuine tilt at the Tour de France in a team that contains two-time champion Froome. The Welshman is more than happy where he is for now but expressed doubts over whether a team can really have two leaders at a race.
He envisages a situation in the 2016 edition where he is a back-up GC rider to Froome, protected in his own right, rather than a super domestique. However, he admitted that there may come a time when he needs to switch teams in order to achieve his individual goals.
"We're both honest enough to know that if the other guy is better we'd commit to each other. I certainly would and I'm pretty sure Chris would do as well. But it's a tough one," he said.
"I can't see Froomey disappearing any time soon. My deal with Sky expires next year but at the moment I don't want to leave for another team and be their leader because Sky is the best place to learn – and be in the best position to get a result. Maybe two years down the line I will feel: 'I know exactly what I'm doing now, and exactly what it takes.' If I have to leave then, then I would."
Thomas remembers Bradley Wiggins' Tour victory of 2012 as "the most impressive thing I've ever seen" and as an achievement that allowed his own self-confidence to grow.
Wiggins represented the fruition of Team Sky's mission statement of winning the Tour with a British rider within five years of their inception in 2010, yet Thomas was touted internally at the time as a rider who could see that goal achieved.
"I didn't believe it. I went 'Pffffff.' Then I saw Brad do it and that flipped the switch in me," Thomas said. "Maybe Shane and Dave saw the same characteristics in me."