Goals from Robert Snodgrass, Grant Holt, Jonny Howson and an own goal from former Ipswich defender Gareth McAuley earned the Canaries a 4-0 win over West Brom to secure safety.
"Staying in this league for Norwich City is a massive achievement, it's as simple as that," said England goalkeeper Ruddy, who was a spectator for much of the match as he made his first appearance since November following a thigh injury.
"It was the same feeling when we got up from the Championship and the same feeling last year when we knew we were safe.
"We just knew what we had to do. Since last week there's been a lot of pressure and a lot of hype, but Wigan losing in midweek helped us massively.
"It's always nice to have it in your hands, not have to rely on other teams' results.
"The midweek Wigan result and Villa's result helped us massively and we knew what we had to do.
"It's always been about us this season, no matter how we've played. We're never looking over our shoulder.
"We want to be in the Premier League on our merit, not because other teams faltered.
"We gave ourselves the best possible chance with a 10-game [unbeaten] run earlier on in the season. We've been a bit patchy since then, but we turned it on and that's all that matters.
"We just knew coming into this game we had to win and we relaxed a bit and played with a bit of freedom. We showed what we're about and what we can do."
Norwich enjoyed periods of success - including that 10-game unbeaten run - and fallow periods this season and Sunday's win was just a third in 20 games.
Manager Chris Hughton, whose side now go to Manchester City free of the worry of the drop, said: "We've not been consistent enough. In the end we got there and we got there in some style."
Ruddy was delighted to return and play his part and hopes Hughton, who was appointed last summer, can now improve on survival.
"Five months has been a long time," Ruddy said.
"It was a fantastic performance from the lads. Everyone to a man was on top of their game and we reaped the rewards.
"The gaffer can put his stamp on it in the summer and rebuild.
"He's brought [Sporting Lisbon striker Ricky] van Wolfswinkel in already, so we look forward to seeing him and what other recruits can come in as well.
"It's going to be an interesting summer."
While there was jubilation for Norwich, West Brom boss Steve Clarke was left to rue a woeful performance, after which he accepted some of the blame.
"If I pick a team and the performance is like that, it has to be my fault," Clarke said.
"I mis-read the game. I didn't think Norwich were capable of causing us so many problems.
"I thought with three front players we could cause them a lot of problems, but we didn't."
West Brom's season concludes against champions Manchester United in Sir Alex Ferguson's 1,500th and final match as Old Trafford boss.
Clarke added: "Our boys have been battling it out all season, put ourselves in a great position early on. The second half of the season has been less exciting, less good.
"Our second half of the season has been poor and the season's slowly fizzling out for us. If I'm being honest, we need the summer to come."