The Liverpool left-back was determined not to lose contact with his Scotland colleagues after November's historic meet-up, when they qualified for a major tournament for the first time in 23 years.
Robertson believes maintaining virtual contact has ensured Steve Clarke's squad are ready to hit the ground running when they begin their World Cup qualifying campaign against Austria at Hampden on Thursday.
But the former Dundee United player also feels the bond they developed in beating Serbia in the Euro 2020 play-offs - and through some memorable celebrations later that night - have ensured the feelgood factor and spirit remain intact.
Robertson said: "With us qualifying in November we then had momentum and it maybe came at the worst international month for that, because you wait another four or five months to play another international game.
"But you could see the boys walking in on Monday with a big smile on their faces, ready to pull on a Scotland shirt again. That's what we have tried to create.
"The feelgood factor is still there in training and the mindset and goals of all the players are pretty clear. You can see that just walking into a room with them all, they are all driven individuals which helps a driven team.
"That's credit to the manager and the coaches, as soon as they have come in they have tried to get that across to us and we have all bought into that.
"When new lads come in, they see the nucleus of the squad and how we approach training, approach games and represent our country, and they buy into it.
"Over the four or five months of not seeing each other it was important we kept in contact, and we did. That's why when we come in here, we catch up with each other of course, but we are ready to work and go again."
That togetherness has not always been there.
The 27-year-old said: "The gaffer asked what was maybe missing when he first came in and I think a lot of us said 'that club mentality'.
"At one time there was a lot of chopping and changing, maybe eight or nine new faces every time. It's hard to then build relationships off the park and build friendships.
"Now we have that nucleus where there's 17 or 18 who are familiar and new lads come in and we make it easy for them to fit in.
"It is a club-like mentality, all the boys get on off the park and we are all close, and that makes a huge difference. It makes you run that extra yard for each other on the pitch, makes you fight for each other that wee bit more.
"On the night we qualified it did more for us than anything because after the game the squad got closer than ever.
"You can see that now, the relationships off the park are probably stronger than they were in October and November, and we want to build on it.
"We’re a relatively young squad, hopefully a lot of us have still got a lot of international football left and the longer it goes, the stronger it gets."