It is such an incongruous and distant memory that it seems like a description of someone else entirely. His lowest ebb came in a game at Tynecastle on October 2, 2011. Celtic lost 2-0 and Commons played as he had for most of that season: poorly. He hardly had a kick all night until he aimed one at Adrian Mrowiec and was shown a straight red card.
It was Commons' 'lost season'. Among all of his Celtic campaigns only 2011-12 stands out as a failure. In his first four months in Scottish football, he scored 14 goals. In his second full campaign he scored 19, and in the current one he is already on 16 and on a rich vein of form which promises to yield many more. But 2011-12? That was the season of the misfiring, sluggish, dare-we-say-it slightly heavy-looking Commons. In the entire season he scored only once. He has been indispensable to Neil Lennon for so long that it is odd to recall a time when he was in and out of the team, sometimes injured, sometimes dropped, rarely looking match-fit.
"The low point was probably getting sent off at Hearts," said Commons, having been named this week as the SFPL Premiershp player of the month for December. "I think I'd been injured or I hadn't played for a little while. I was on the bench, just playing a bit part, being a sub here and there. I got the nod to play and I got a straight red. I just remember coming back in the changing rooms and thinking: 'What's happening here? I've not scored a goal. I'm not playing. I'm getting red cards for reckless challenges. That's not me. I don't do that'. Yeah, that was a bit of a dark time.
"It was one of those seasons that's probably never happened in my career before. I'd gone from coming in and scoring goals, playing a big part and doing really well, to picking up injuries, not playing well, being in terrible form. I couldn't argue about not playing.
"I just didn't really have the answers. When you're playing badly and you're injured all the time you tend to try even harder and you end up making yourself worse. It was a bit of a learning curve for me."
At 30, Commons now has experience, but he has always had intelligence. He can put the episode into perspective, especially now that he has delivered a campaign-and-a-half of vibrant form since the lost season. "Did I ever feel like leaving Celtic? No. You have to take football as a package. Bad times make the good times even better. Footballers don't just have illustrious careers and great highs all the time.
"You have to have the lows to make the highs as good as they are. I'm probably grateful that these times - when I'm enjoying it, picking up awards and scoring goals - keep my feet on the ground, because I know how bad it can be.
"I train every day, as well as I can, to stay in the starting XI. I know the gaffer can change it whenever he wants because we've got a lot of players always itching to start the game. So I try to keep my feet on the ground. I've got to keep performing week in, week out so that I'm one of the first on the team-sheet.
"I probably took it for granted when I expected to be playing week in, week out. And when you are playing at club of Celtic's calibre then it's brilliant playing in front of the fans, it's brilliant winning trophies, it's superb playing in the best competition in the world [the Champions League]. But when you are not involved it's one of the worst places because you're missing out."
Celtic are in an enviable position as they face Motherwell at Parkhead this afternoon. After 20 games last season they were on 40 points and six clear at the top. This time they are on 54 and ahead by ten. The team has been far more consistent in its results around European ties this season. "I think part and parcel of it was the Champions League and the fact we had a squad which was relatively inexperienced in trying to balance Europe and domestic games.
"We knew going into games we could lose the odd point and if you're not 100 per cent focused in games then you will get done."