The 24-year-old says his decision was rooted in his firm belief that Signal Iduna Park was the right place for him to further his career
The 24-year-old completed a club record €27.5 million (£23.8m) switch to Signal Iduna Park this week and, while a number of other teams were rumoured to be interested in his services, including Liverpool, Mkhitaryan has revealed there was only one club for him.
"I went with my heart, and I hope the club never regrets spending a single cent on me," he told reporters.
"I came to help the club achieve its goals."
Meanwhile, the Armenia international also refused to be drawn on comparisons between him and predecessor Mario Gotze - who left for Bayern Munich earlier in the summer - and says his new team-mates have given him a warm welcome at the club.
He added: "He [Gotze] is a very good player, but a different type of player than I am.
"I have been very well received by the other players, which has helped me a lot. They have all taken care of me and it has really made me adapt easier."
Mkhitaryan netted his first goal for the club in the 3-1 victory over Basel in a friendly on Wednesday.