The centre is now looking to round off the Six Nations campaign with a rare victory over Ireland but admits he would have struggled to cope with the French setback earlier in his career.
Harris, who comes across as a thoughtful, honest individual, has since learned how to deal with the slings and arrows of professional sport.
Nevertheless, the missed opportunity at Murrayfield, when Stuart Hogg fumbled his long pass, preyed on him in the days after the 36-17 defeat.
“These moments just happen so fast,” reflected the Gloucester player. “If we’re talking about that pass, it’s a fraction. If that’s a fraction closer, everyone is like: ‘What a pass’.
“But it wasn’t. It probably wasn’t a great pass. But it’s fine margins. I’m experienced enough now that I can park these things and move on.
“It did play on my mind a bit over that week. But you have to just get over it and get back on the horse.
“No one’s really going to be thinking about it in the next tournament or in a few weeks’ time. You need to just crack on.”
The mistake was compounded by France going up the other end of the pitch almost immediately to score their third try of the match and go in at the interval 19-10 ahead. Scotland never recovered and conceded another try just after the break, with Harris playing no part in the second half after failing a head injury assessment.
“I was frustrated that I was off at half-time. I didn’t have the opportunity to have another crack and finish the game off doing something more positive,” he said.
“I was frustrated and the team were frustrated with the performance as a whole. Someone else can say if it was a defining moment in the game.”
True to his word, Harris “got back on the horse” in Scotland’s next match, playing a key role in the 33-22 win over Italy in which he scored two first-half tries.
The 31-year-old felt that setbacks earlier in his career helped him deal more readily with what happened against France and acknowledged that his younger self would have struggled.
“It takes someone with a strong mind to deal with things like that,” he said. “Everyone’s very different when it comes to that sort of thing.
“Some people can just move on quickly. With some other people, it takes a while.
“I’ve had other moments in games, not that one, but earlier in my career where I’ve had a bit of a shocker and it’s really affected me. Back then, I wouldn’t have played well for two or three months after it.
“It’s moments like that you remember and realise that you can get over it.”
The final staging post in Scotland’s 2022 Six Nations campaign is Dublin and while the visitors are out of the running in terms of the title, success on Saturday would add a gloss finish to a largely underwhelming championship for Gregor Townsend’s side.
“To win this one would be massive,” added Harris. “It’s the difference between finishing fifth and potentially third. It would be quality for us as a group to finish on a high in what’s been a bit of an up and down tournament.
“We obviously got the result out in Italy. It wasn’t an amazing performance but we got the five points. Everything is just now focused on Ireland and trying to improve our own game and give it a good crack over there.
“They’re a very good side aren’t they? They’ve been quality for a long time and to go to Ireland to play them is especially hard.
“It’s St Paddy’s weekend as well so the crowd are going to be up for it so it will be quite a hostile environment I’d imagine. I’ve only played there once with a crowd and I remember it being pretty intense. But you’ve got to relish that and enjoy that. We’re mostly looking at ourselves and how we can improve and try to impose our game on them.”
Ireland still have designs on the title and know that if they can beat Scotland then a slip-up by France against England in Paris on Saturday night would see the silverware head to Dublin.
Given the Scots’ dismal record in the Irish capital - they’ve not won there since 2010 - nobody is giving the visitors much of a chance. The hosts are heavy odds-on favourites but Harris is phlegmatic.
“I’m not too bothered about what the outside thinks, with all due respect,” he said. “We just have to look within the group and at what we’ve achieved in the past. I’ve never been to Ireland and won – I’ve been told we’ve not won in Dublin since 2010.
“So it’s been a while. It won’t be an easy game just because we’ve won other away games over the past year or so. We need to be on it for 80 minutes and mentally switched on and stick to whatever the gameplan is going to be.”
As a veteran of the hoodoo-busting away wins over Wales, England and France, Harris will go to Dublin without trepidation. He is likely to have Sam Johnson alongside him, with the Glasgow inside centre restored to the team for Rome after being overlooked for the defeats by Wales and France. The pair have forged a good understanding and have played together in some big wins. They contributed three of Scotland’s five tries against Italy and Harris believes Johnson had a point to prove in Rome.
“He was frustrated not to be involved after the England game. But he was hungry to perform and show his worth.”