Lukaku discussed his decision on the Josh Hart Podcast.
“I was gone, I was going to Chelsea," he said.
"I was looking for an apartment, an apartment for my mum to stay in close to the practice facility, so I don't have to drive too far. And then Man U came.
"At Man U everybody was... I felt the trust more, where everybody wanted me to be there and that's the true story.
"People say 'Yeah, my agent (Mino Raiola)' and stuff like that - my former agent at the time - he did his job, he got the best opportunity for me, but the people wanted me the most and that was Man U. Everybody was wanting me. There was no doubting.
"They came and they told me - I was in New York - I get a phone call from this number and I'm like, 'Who's this?' Pick up, Jose Mourinho. 'Rom, how are you doing?' I'm like, 'Yeah, what's up, boss?'
"'I'm gonna get you back, we're gonna pay £75m plus £15m in bonuses (add-ons) by next week, so I expect you in LA. So go and do your s*** in LA and I'll see you after [in pre-season]'. I felt the dude was lying, like 'I'll see you'.
"Then the next thing I know, I wake up and had to go back to Everton on the July 7 and July 6, I wake up in the morning and I see they've agreed the deal, so I'm like, 'Man! They came in hard!'"