Bullemor made his NRL debut at the Broncos last year but the club struggled during his 25-game tenure.
The 21-year-old told News Corp he wanted to taste success so made the move to Manly, who finished fourth on the ladder this season.
“For myself, I got to a point where I felt like I wanted to be succeeding more than I was,” he told The Daily Telegraph.
“I wanted to break out and try to better myself. I felt like sometimes a change is a good way to do that. I had a lot of success in previous examples where I have moved towns or schools or implemented a change in my life.
“It really makes you work a bit harder and can open up a new range of possibilities, expose you to new ways of doing things.
“I was lucky that Manly came about. It looked like a perfect fit to me. It is obviously a team that most people would love to be part of – they are flying pretty high and they seem to have lots of aspirations to go better than they did last year.
“That was a good sign in my mind.
“In all honesty, there was a fair bit of thought and consideration leading up to it but once I looked at it and really understood how I felt and what I thought was the right move, I have been really steadfast in it since then/.
“I haven’t looked back. It (Brisbane) is a club I grew up supporting and wanting to be part of. I was lucky enough to have been part of it.”
“(Manly) had a good season last year and they’re all really keen to improve on that.”
“The impression I have got from talking to some of the guys at the club is that they are not resting on their laurels. They are not happy or satisfied with a top-four finish.
“They are really talking about going that extra mile, winning the comp and playing in a grand final.
“As a football player, that is the stuff you dream of and that is what I want to do.”