TO HAVE any chance of realising your dreams, you have to ensure you are rooted in reality.
It's a principle which has served Johan Mjallby well, both as a player, and in management.
Now that he has decided to strike out from what has been his adopted home for the best part of the last two decades, it will travel with him wherever his career carries him.
His attention to detail, allied to a drive and unwillingness to throw in the towel, no matter how heavily the odds are stacked against you, have made him a solid ally for Neil Lennon as they have rebuilt a Celtic squad which was on its knees after 10 months under the charge of Tony Mowbray.
As a player, Mjallby knew all his limitations, but preferred to focus on his capabilities.
His early months at Celtic were not his best as his rugged approach and desperation to impress brought him more bookings than plaudits.
However, a drop back to central defence brought out the very best in him, and, through his personality, those playing alongside him.
They were qualities which impressed Lennon when he arrived a few years later, and which came to mind when the Ulsterman was invited to take over as manager of the club in March 2010.
Hence the call to Sweden where Mjallby was indulging in a bit of media work while waiting for the right opportunity to step back into a game he had served so well as a player.
The clever money was on the club where he first made his name and where he eventually had to call time on his career through injury, AIK Stockholm, recognising what they had right under their nose.
But, Lennon got in first, and the giant Swede with the even-bigger persona had no hesitation in answering the call.
When asked if he foresaw just how successful they would be in what was their first venture into management at the then-overcast Paradise, Mjallby emphatically replied: "Definitely.
"It maybe sounds a bit cocky, but I've always been a winner.
"In every club I have played for, I have won titles.
"I won the league with AIK twice and the cup twice. Then I had the chance to go to Celtic, where we were successful (three titles, two Scottish Cups and two League Cups, plus a Uefa Cup final appearance), especially under Martin O'Neill.
"I only spent a few months at Levante, so I didn't have the chance of winning anything there.
"So, I expected us to do a very good job (in management), to improve the team, which we have done.
"With my past here, I know it's all about winning titles and playing football in a certain way, being very attack-minded."
Which is what they have got their Celtic side to do.
Of course, the challenges as part of the management team are very different to those which confronted Mjallby and Lennon as team-mates.
For starters, there is no Mjallby nor Lennon in the current team. Neither is there a Henrik Larsson, Chris Sutton, Paul Lambert, Lubo Moravcik nor Stiliyan Petrov.
Times, and budgets, have changed since those days when welcoming a new £6million signing was commonplace.
But, for all the quality which oozed out of the sides built by O'Neill, they could not get beyond the group stage of the Champions League.
At their second time of trying, Lennon and Mjallby found the way with a squad worth considerably less than the ones they had played in.
It was a kind of rite of passage for the assistant manager, who admits that being on this side of the white line is a completely different experience, and - as he prepares to pack his bags and head out of Parkhead for pastures and challenges new - one with which he is still coming to terms.
He said of life as a coach: "I'm really happy, but it is a different feeling in management because, as a player, you are a bit more egotistical and you think about yourself.
"You think about the team. But, even in training, you do your work, and a little bit extra after it, but then you go home."
He went on: "In management, you put in many more hours. You look at the opponent, try to monitor them, put the tactics up, your team selections, and you have training to think about.
"So, it's a different feeling. You feel more joy and more satisfied in management winning titles.
"As a player, it is something you don't really look back on until you have finished your career.
"So, it is different, but it is all about winning, and I've always been blessed to have the opportunity to win a lot of titles."
In whichever technical area he next appears, Mjallby will endeavour to continue this streak.
There will be no shortage of offers, and in recent weeks the 43 year-old has been linked with a move back to his homeland where an already-impressive reputation has been further enhanced by his achievements as Lennon's very able lieutenant.
Mjallby - in keeping with his Scandinavian heritage - was the cool customer when Lennon was living up to his fiery reputation.
Even when the manager was being attacked by a Hearts fan in the technical area at Tynecastle in 2011, Mjallby was content to stand aside and allow coach Alan Thompson to jump in and apprehend the assailant.
Given Mjallby's tough-as-teak physique- having bounced off him in a small-sided game between the backroom staff and the Press, I speak from painful experience -that was fortunate for him.
But, as ever, he had Lennon's back, and has proved to be a very important support act throughout their time together in the manager's office, training field and on the touchline.
Lennon is expected to promote coach Garry Parker to his No.2 position, but Mjallby's are very big boots to fill.
When he goes, he believes he will leave behind an ethos which can sustain and prosper.
"You want to be very, very attack-minded, and you want to go forward and score a lot of goals," said the Swede.
"But you need to find the right balance. This year I think we have found it because we have been very solid at the back and not conceded many goals.
"That obviously pleases me a lot as a former defender.
"Last year, we conceded many more goals which really were not that great, and lost too many games.
"We should always be attack-minded, but it is a question of finding the right formula and balance.
"In that department, this season has been very good."
So it is with considerable satisfaction Mjallby will exit stage left, and to a rousing round of applause from everyone involved with the club.
His departure will increase the speculation Lennon could soon follow as this will be perceived in some quarters as the end of a short, but successful, era for the club.
Only time will tell. But, what is already clear is that Mjallby is not finished with the game, just seeking a fresh challenge.
As he said: "You always have to dream, and you try to be a step ahead of the competition."
In management, just as he was in playing, he continues to be just that.