Cattermole and his team-mates woke up on Thursday morning to the realisation that they will be playing Barclays Premier League football once again next season - something which looked a remote possibility just a few weeks ago.
They will do so by virtue of a remarkable series of results which has seen them take seven points from a possible nine from trips to Manchester City, Chelsea and Manchester United, a maximum return from Cardiff's visit to the Stadium of Light and Wednesday night's 2-0 home victory over West Brom.
However, while Wearside is celebrating now, there is also an acknowledgement that the lessons of an eventful campaign must be learned.
Cattermole said: "I think there will be a day in the summer when we wake up and think, 'That was some achievement'.
"It hasn't sunk in yet, but, as lads, we have got to thank everyone who has had to deal with the whole season.
"We have stuck together and come through it
We don't know how, but the results have been absolutely incredible
There isn't another word.
"We have pulled it off and we have got to be looking at pushing the other end of the table next year
That's what we have got to aim to do.
"It was a bit too close for anyone's liking
We have got to learn lessons from that and improve, because when you see nights like (Wednesday) night and the Cardiff game with the place full, it means a lot."
The fightback inspired by head coach Gus Poyet has been little short of miraculous.
A 1-0 home defeat by Everton on April 12 left the Black Cats at the foot of the table and seven points adrift of safety with just six games remaining.
But it was then that something remarkable happened: they remembered how to win football matches.
Having been denied victory at Manchester City only by a late goalkeeping error, they defied the odds to beat both Chelsea and Manchester United on their own pitches to pave the way for a completely unexpected great escape which was sealed against the Baggies with a game to spare thanks to goals from Jack Colback and Fabio Borini.
Cattermole, whose own form over that run of games proved inspirational, said: "When everyone is writing you off, it's your job to go out and play.
"We are all competitors and we don't give in
That's where we are as people and that's probably why we have made it in the game
We have shown our character.
"You can say all the cliches, but, ultimately, it came down to us playing some good football and sticking together."
Poyet celebrated on the pitch with his players after the final whistle, having completed the mission he was handed last October.
A man who wears his heart on his sleeve, he admitted the enormity of the situation had got to him at times, and there was one overriding feeling as he and owner Ellis Short congratulated each other on an emotional evening on Wearside.
Poyet said: "I think there was a little bit of relief for both, for him and for me."
The 46-year-old Uruguayan will prepare his players for Sunday's final-day clash with Swansea knowing the pressure is off, and already turning his attention to preparations for the new campaign and the more immediate task of dealing with a host of out-of-contract players.
By contrast, opposite number Pepe Mel will head into Sunday's showdown with Stoke looking for a reaction after a poor first-half display in the north-east which left his side with a mountain to climb.
West Brom are not yet mathematically safe, although Norwich would need them to lose to Stoke and beat Arsenal with an improbable swing in goal difference to overhaul them.
It appears unlikely that out-of-contract Zoltan Gera will get his swansong in a Baggies shirt against the Potters, having failed to train since suffering a hamstring injury last month.
Mel said: "Zoltan Gera has not trained with the team since his injury, so it really is very difficult, almost impossible, that he will play."
Source : PA
Source: PA