He added: "I thought I'd stay here for the rest of my career and I was looking forward to helping Reading get back into the Premier League."
"Everything was done and dusted and I was looking forward to signing [a new contract], then suddenly you get the last minute phone call saying that Harry Redknapp wants to see you."
Little made only two appearances after an Achilles injury last season and he said it made him determined to play in the Premier League again.
"Their first three fixtures of the season are Chelsea, Manchester United and Everton, the same that we had with Reading last year which I missed out on.
"There's also the Charity Shield against Manchester United at Wembley and playing in Europe, it was just too good an opportunity to turn down."
Little, who has known Steve Coppell since he was nine, said telling the Reading manager he was leaving was particularly tough.
"I had a lump in my throat telling him, I couldn't get the words out. But he wished me all the best and we'll still stay in touch.
"We've been through so much as a club, who can forget that promotion season when we went 33 games unbeaten.
"It makes a special bond, I get on so well with everyone, it's strange and I'm sad to be leaving."
Little is the first high-profile Reading player to leave the club since relegation and he says it is up to the club whether more follow.
"I'm sure there will be interest but I was on a free transfer, other players can't just up and leave.
"It's up to the club, if bids aren't good enough, they can say 'no'."