Who could have predicted the entire landscape of the game in the country would have been altered so dramatically?
But, for Celtic, they can head into the new year feeling content that they have come through it in a stronger position, and have so much to look forward to in 2013.
Neil Lennon, in particular, can look to the future as a much better, more confident manager, able to draw on the experiences – good and bad –which have carried him to this point.
His status within the game has grown, and that can be said for the club as a whole, thanks to regaining the SPL title and going on to book a place in the Champions League last 16.
It's worth taking a moment to consider how far they have travelled in such a short period of time.
It was only this day last year that they got back to the top of the SPL.
By May they were celebrating being champions for the first time in four years.
And by the beginning of December, they had booked their place in the Champions League knockout round.
It's some going, and everyone involved deserves credit.
It's a reminder just how quickly fortunes can change, if you remain strong and convinced you are doing the right things.
Neil will appreciate that more than most, and his development as a manager has been very impressive.
Claiming your first title as a Celtic manager is such a big milestone for anyone, and only when you have achieved this do you appreciate just how much pressure has been lifted from your shoulders.
Now Neil has added success in Champions League to his CV, and who is to say they can't push on even further than the last 16?
Gordon Strachan is the only other Celtic manager to have got the club this far, and I reckon this is an appropriate time to reflect on what an achievement that was.
When he took over in 2005, the club was cutting back in an attempt to stop losing money.
Gordon had to overcome a horrible start, losing 5-0 in Bratislava and crashing out of Europe.
But he bounced back and reclaimed the title, which he kept for the next three years.
At the same time, he reached the Champions League last 16 two years running.
For me, that was a phenomenal achievement, which did not get the same kind of attention as has been given to this season's qualification.
Like Gordon, Neil has had to show his resilience to come back from early European disappointment, the defeats to Braga and Utrecht which saw them exit Europe before he really had his feet under the managerial table.
Now, the bar is being raised the more big wins he oversees and the more trophies he brings to Celtic Park.
But Neil appears to be thriving on this, and I wish him every bit of luck his effort deserves going into the new year.
Here's my look back at 2012:
IT has to be the night Barcelona were defeated at Celtic Park, a result which made all of Europe sit up and take notice.
But there's a case to be made for the most important event being the return of the SPL title to the club. Without that being achieved, the confidence to take on the best in the world would have been harder to find.
There have not been too many for Celtic in the last 12 months.
An obvious negative was losing the League Cup final to Kilmarnock. But Killie just had one of those days, with their keeper, in particular, having the game of his life.
For me, more disappointing was the way in which Celtic went out of the Scottish Cup to Hearts at the semi-final stage.
But both defeats are quickly forgotten when you look at the bigger picture.
Gary Hooper and Victor Wanyama have both enjoyed an excellent 12 months.
But I believe the player who has been most important to the team has been Fraser Forster.
I don't know what happened, but he suddenly became transformed from a nervous loan signing to a very confident and accomplished permanent No.1.
He is now pushing Joe Hart for the England spot, and deserves to be given his chance by Roy Hodgson.
The confidence Fraser is exuding is permeating to the players in front of him, and can be as valuable as any saves.
The Treble is so tough to achieve, because, on any given day, you can make a slip and crash out of a cup.
But I believe it's a viable target given the way Celtic are performing and their current position in the SPL.
Retaining the title is the No.1 priority, not least because there is only one Champions League qualifying round spot up for grabs this season.
I don't think they are necessarily finished with that competition this time around. The last eight is not beyond them, though Juventus are a very tough opponent.
My contacts in Italy reckon that they consider themselves invincible on their own pitch.
When you consider Celtic's record at Parkhead, it has all the makings of two very exciting nights.
This time next year, this tie could be what we are all still talking about.