The 58-year-old is yet to defeat the Canaries as Town boss, as he prepares for his sixth derby in charge.
"If you come to both clubs you get well received, it's a nice place to come to, except for when Norwich and Ipswich play each other," said McCarthy.
"They hate each other, and I've been surprised at that."
He added to BBC Radio Suffolk: "The same points are at stake but of course everybody associated, from both sides, all want to win because it's a derby."
Norwich's recent record in the derby includes a play-off semi-final victory on their way to promotion to the Premier League in 2015, though they were relegated the following season.
Alex Neil's Canaries, seven points off the top six, are also ahead of McCarthy's side in the table, and the former Republic of Ireland boss says he thought, after a strong start to the season, they would "at least" be in the play-offs.
"A point at Norwich is certainly a good point, said McCarthy. "I'm not bothered if you're a supporter, a pundit, a journalist, a team that's spent that amount of money and the squad that they've got.
"I'm not bothered what anybody else says - if we get a point there I'll be happy with it."
Neil's side suffered defeat at Championship strugglers Burton last time out, ending the Canaries' six-match unbeaten run, and the manager admits they have "very little room for error" in their play-off push.
And the Scotsman believes that their next run of fixtures, which includes a match against fellow play-off hopefuls Sheffield Wednesday, could prove decisive in their race for the top six.
"For the importance of where we're going and if we're going to get there, the next three games are going to be crucial," Neil told BBC Radio Norfolk.
"I think the derby has come at the perfect time because we need to respond, and let's hope we get that response."
Ipswich Town manager Mick McCarthy says he has been taken aback by the hatred between his side and East Anglian rivals Norwich City.