Everton's new record signing Romelu Lukaku insists he owes Chelsea a debt of gratitude but feels Goodison Park is the best place for him to become a better footballer.
The 21-year-old Belgium international completed a club-record transfer deal of £28million after signing a five-year contract with the Toffees.
Lukaku, who played just 15 times in three years at Stamford Bridge, spent last season on loan at Everton and that was a decisive factor in him choosing to make the move permanent as he felt he received the support and belief which was lacking at Chelsea.
"I don't have hard feelings against Chelsea. They gave me the opportunity to come to England and gave me high hopes of playing football," he said.
"I trained with world-class players and worked under world-class managers and without them I wouldn't be here.
"But last year was a very good year and after a short period of time I had the feeling it was the best place to grow as a young footballer.
"The manager has been very influential. He is someone who knows football, someone who can develop me as a player and make us better as a team - and that is something I need as a young footballer.
"I needed to be in the place where it felt right and here I have the confidence of all the technical staff, the trust of the supporters as well and I can grow and develop.
"I have a very good relationship with the players and staff so for me this is the place where I belong."
Martinez said the deal, which eclipses the £15million deal for Lukaku's compatriot Marouane Fellaini when he moved from Standard Liege in 2006, had been almost a year in the planning.
But the successful completion meant the club had sent out a strong message.
"It is not just one of those important days for the season but it is a very significant day in the history of our football club," said Martinez.
"The feeling in the dressing room was to get him back on a permanent basis to get some continuity and grow into a very successful team.
"That is why we are so delighted. It is not something which has happened overnight, there has been a lot of work and support from the chairman and the board has been very important in being able to see Rom back at the club.
"It is fair to say Romelu was our number one target to bring in and the pursuit was relentless but it had to be a record transfer and it is worth every single penny and effort we put behind it.
"At 21 he has already scored over 30 goals in the Premier League and in my eyes the target is for him to become one of the best world-class strikers.
"To have a footballer of Rom's calibre on a permanent basis it means there had to be a lot of long-term planning and work behind the scenes but, more importantly, his potential his huge."
Lukaku admitted he had an inkling in Everton's final match of last season he would be returning.
"For me I decided very quickly I wanted to come back here because it was a good step for me," said the striker.
"Expectations for myself are very high but when you have a manager who wants to push you and the team it is a perfect environment for a young player to grow.
"I am 21, it is time to have a stable career as well so it was important to be somewhere where you are there to win titles.
"I think I can improve in every aspect of the game. My goalscoring record says a lot but if I want to win titles I have to get better in everything."
Meanwhile, Chelsea manager Jose Mourinho believes the deal is good for all concerned.
He told a press conference in Holland televised by Sky Sports News: "He wanted to play for Chelsea but wanted to be the first-choice striker. That's very difficult to promise.
"Everton made an important offer and financial fair play is something that is always behind the thoughts of the board...this leaves Chelsea in a great position.
"The important thing is he's happy and things work well for him, he's a good kid."
Lukaku admits he did not have any contact with Mourinho immediately before his departure.
"I spoke with my agent and then from that moment on I left it up to him as I was on holiday," he said.
"I made my decision and then didn't speak too much about it."
Asked whether he had spoken to the Portuguese at all, he added: "No - I think he was busy with the game tonight (against Vitesse Arnhem).
"Things happen and sometimes it's not meant to be. Chelsea is a big club and sometimes it is difficult for young players to come through.
"I want to have a good career and I didn't want to spend 10 years on the bench, I wanted to make the best out of every year.
"This is a club with a lot of ambition and the right place to be.
"You don't have to have regrets in football. Choices have to be made.
"Mr Martinez will be one of the top managers in the world and for me to work under him now is the best thing that could happen for me."