Dier completed a move to White Hart Lane from Sporting Lisbon on Saturday, signing a five-year deal, having spent his earlier career in Portugal after moving there with his family at the age of six.
"It's always been my ambition to come back to England and play in the Premier League so I'm really happy to do that," he told Spurs TV.
"It's kind of a strange background [coming through the youth system at Sporting as an English player]. Everyone seems surprised by it, but I didn't go there because of football, it just happened that way.
"I moved there because of my family. We moved there when I was six and I got picked up by Sporting when I was eight and went through their youth system all the way to the first team.
"At the beginning it was hard because I didn't really speak the language. I was seen as an outsider when I was younger, but once you've got the language it's really easy. I don't think now they see me as English, they pretty much see me as one of their own."
Dier knows exactly what to expect from the Premier League and will link up with some familiar faces at his new club, having played with the likes of Harry Kane, Tom Carroll and Ezekiel Fryers in England's age-group squads.
"It's still the only league really that I watch, even [when I was] out in Portugal," he added.
"It's on the TVs there and it's the biggest league in the world in my opinion. Every year I've been there I've watched all the Premier League games and obviously watched a lot of Tottenham.
"I've always enjoyed the way they play their attacking football and the way they play - coming from Portugal that suits me and this season I just want to adapt really quickly to the Premier League and just do the best I can.
"Harry and Tom I've been in a lot of squads with, Harry especially since I was quite young, so I know them quite well. They're really good lads and I know Zeki Fryers as well, so obviously that will make it easier. It always helps when you know a couple of the lads."