The Blues finished second in the Championship to bounce back at the first time of asking.
But as a recently relegated side with parachute payments, the likes of Coventry City, Millwall and Middlesbrough have undoubtedly had more support from neutral viewers than Town.
Earning promotion in light of that felt extra special to O’Shea.
“Nobody wanted us to do it this year,” he said. “Everybody wanted to see us fail.
“I’m just proud of us. We believed in it. We always thought we could. We proved it to ourselves, which was the main thing.
“There’s pressure there. Everybody expected us to go up, to do this. They wanted to see us fall and we didn’t.
“We walked the walk, which was the most important thing.”
This campaign was always going to feel unique. Town are so used to being the underdogs, but this time, they came in as heavy favourites due to the quality in their squad and some of the reported transfer fees.
Promotion felt like an inevitability for those on the outside looking in, but the reality of coming down from the Premier League into the Championship can be much harsher.
“It’s the polar opposite to last season,” O’Shea explained. “It’s different.
“It takes a while to get used to it. We had to understand that teams were happy just to disrupt us in whatever way they could this season. It probably took us a while to come to terms with it.
“I think we’ve done unbelievably well. It’s been a difficult season.
“You look at the teams that came down with us last season. Obviously, Southampton are doing brilliant now. Leicester find themselves in League One, unfortunately. It’s tough. It’s not easy. Nothing’s given to you.
“Everyone expects Premier League teams to come back and to step back up straight away, but it’s not like that.
“We’ve done it. That’s all that matters.”