Lukaku was a summer 2011 arrival at Stamford Bridge for a fee of £17million but rarely featured under manager Villas-Boas, instead spending the majority of the season in the reserves.
He was also not registered for the Champions League by the Portuguese manager and only made his first start for Chelsea in the Premier League in May – well after Villas-Boas, now in charge of Marseille, had been sacked.
Roberto Di Matteo, Villas-Boas' replacement, led Chelsea to an unlikely win in the Champions League and insisted that Lukaku, along with injured and suspended players, travel with the squad.
"(Roberto) Di Matteo told me that I would stay with the group until after the final," Lukaku told Het Laatste Nieuws.
"He thought everyone should come along, including the ones who were suspended and the few boys who were not in the Champions League squad. I am also grateful to him for that."
He added: "This win is one of the things I've always dreamed about. You want to celebrate something like that with the team at that time.
"That is nice in itself at the age of nineteen. I am happy for the whole club, but there is one man who took a lot from me: the previous trainer (Villas-Boas). I will never forgive him for that."