Lukaku’s move to Serie last August brought to an end a two-year spell at United that saw him face regular criticism for his performances, particularly in his second season with the club.
United boss Solskjaer said in September that it had been the “right decision” to let Lukaku leave, as it allowed first-team opportunities for youngster Mason Greenwood.
In a YouTube interview with Ian Wright, Lukaku said: “One bad year can happen to everybody in their career. It was just done for me. You know what happened behind the scenes, it was just done. For me it was done.
“It was a difficult situation where for myself I had to make a decision where I have to go somewhere where I can learn other aspects of my game and work with somebody that wanted me as well.
“Ole wanted me to stay, but I told him I was over. I didn’t have the energy. All credit to him because he’s been a man and he helped me make the move away.”
After a challenging start to the season, United’s form has picked up to put them in contention for a top-four Premier League finish, while they remained in the FA Cup and Europa League before football was suspended by the coronavirus pandemic.
“They’re going the right way because they’re bringing in the right players,” Lukaku said. “Ole is doing a good job and the results are going for them. I’m wishing them nothing but the best.
“It’s a club that gave me a platform that I’ve never seen in my life, so for me to be disrespectful about Man U or any other club I played for in England I think is a bit childish. I think I went past that stage of talking back to people.”
‘Close call between Inter and Juve’
Lukaku scored 42 goals in 96 appearances for United, but has scored at an even greater rate since arriving at Inter, where he has struck 23 times in 35 games.
The 26-year-old revealed it was a “close” call as to whether he joined Inter or Serie A rivals Juventus, but that the Milan side’s head coach Antonio Conte played a crucial role in his decision.
“It was close. It was really close but my mind was always set on Inter… and the manager,” Lukaku said. “When I was a kid, Inter was my team in Italy. I looked up to Adriano and Ronaldo.
“Obviously when Inter came, the club, the manager Conte that wanted me at Chelsea and when he was at Juve as well, I was like now it’s time to go over there and see what it’s like, but just keep my head down and work.”
Lukaku has been in quarantine for nine days as Italy remains on lockdown because of the coronavirus, with the country the worst hit in Europe.
The former Chelsea revealed that he is unable to see his mum, who suffers from diabetes, and has also not been seeing his young son.