But the Englishman knows that the Hoops will have to raise their game to another level from last term if they are to make it out of a group containing Barcelona, AC Milan and Ajax.
"Last season has been and gone. It's all about this season now," said Forster, who had been linked with a move to Portuguese giants Benfica.
"We have a fantastic team spirit, probably the best I have ever known, and we'll see what we can do now.
"Every season seems to be a big one now. We will just keep ourselves going.
"We have lost a few players since last season but it was a key aim of ours to get back into the Champions League because this is where we want to play.
"It was a fantastic year last year, but we need to do it all again now and it's nice to get the chance to be back in there.
"It is a great standard of football."
It has been quite a week for Forster.
Recalled into the England squad, the giant keeper can afford to draw a satisfactory conclusion from the week that was.
"From a personal point of view, I think it was always going to be crucial to get into the Champions League," he said.
"There was some talk of interest [from Benfica] but I don't really know anything about that. To me it just means that you are doing something right."
Desperate to land a place in Roy Hodgson's England squad for next summer's World Cup finals, there was always a sneaky suspicion that Forster may have been tempted to go elsewhere in search of a bigger platform in which to impress himself upon the England boss.
So Celtic's progress into the group stage of the Champions League is particularly poignant for the keeper, who is well aware that it gives his chances of making the England squad a massive shot in the arm.
Last term he was hugely influential for Celtic in the group stage, with outstanding displays against Barcelona that earned him accolades from further afield than the place where he plays his football.
The opportunity to impress on that stage again is a critical one for Forster, and he knows it.
"A club of this size will always look to be in there with the best teams in Europe because that is where we should be playing," he said.
"It is a tremendous competition and one which every player wants to be involved in.
"It is brilliant for everyone involved not just with Celtic, but for the Scottish game because it raises the whole profile of it."
While Celtic made an impression in the elite tournament last season by making their way into the last 16 of the competition, they will be competing with a very different team this time around.
And it remains to be seen whether or not they can live up to the standards they've set for themselves.
Certainly, though, Forster believes that the Champions League itself can bring out the best in them.
He added: "The European nights here are something special and you can tell that from the way the fans react to it.
"They were extraordinary for us against Shakhter Karagandy. It is a cliche but they really do act like a 12th man and I'm sure they will be just as important for us again in the group stage."