Having broken into the first team again Ashton returned to try-scoring form with 33 tries in 48 games for Saints over the last two years as well as a scintillating start to his international career.
And Ashton, who admits he came close to turning his back on union, is now relishing the variety provided by the 15-man game.
"There are so many different aspects to it," said Ashton who finished as top scorer in the RBS 6 Nations with a record-equalling six tries.
"There's a lot more to it and no two games are ever the same.
"What I enjoy about it is that every minute can be different - you're not just having six drives then kicking.
"But it looked for a while that I was going to have to go back and apologise for making the wrong decision by going to rugby union.
"There was a point where I was still not playing for Northampton and I was only just making the bench.
"Thankfully, it seemed to just click and now I'd like to think I know how to play the game.
"I still have to learn a lot but I think that comes from experience."
Ashton was part of Northampton side who took another step to a league and European double with a convincing 23-7 win over Perpignan in the Heineken Cup semi-final on Sunday.
And with nine tries in 12 tests for England, he admits he feels more at home in his new code than he did in his time with Wigan.
"I'm enjoying it more so now because I feel like I fit in a bit more in rugby union.
"Sometimes rugby league's a bit harsh on people and you have to be quite a strong person to survive in that league.
"Because of the kind of people and the team that we have here at Northampton I think I fit in more.
"I do think of what would have happened if I had gone back, but it didn't and I never really got to that point.
"The reason I came down here was not to be a failure in this game. I didn't realise quite how hard it was going to be because I was only 19 at the time.
"It is a career-long learning curve for anyone who switches code.
"It just seemed to click for me and I started to understand what I had to do.
"Before that, I was just running around and doing stuff that it looks like you can do but when you're out there it's completely different in trying to understand it.
"I think it came with learning it in training and watching a lot of rugby."