"It's been on the table for the best part of a couple of months," he said. "A lot of sleepless nights, a lot of U-turns here and there but I'm glad in the end I made the best decision for me and my family."
Asked about his reaction to those who say he's leaving too soon, Luatua said: "I can understand that and I appreciate that. In a sense I think that's a bit of a compliment, people wanting me to stay and thinking I haven't reached my full potential here [and that I] could do more for New Zealand Rugby. But ... it's a good opportunity and a good fit. I think Bristol is a great city and I'm fortunate to have a head coach that I guess will understand me and my goals and aspirations over there.
"At the same time I can secure the future for my family. That's a big pull, to give back. My family don't expect much. They know I do what I do and that I give back when I can, but in this way I can actually make a difference."
The tall flanker or No8, who adds depth to any squad for his ability to play lock, is the youngest of five children, and said the ability to give back played a big part in his decision.
"As I have got older I've come to realise it wasn't just mum and dad that made a lot of sacrifices," he said.
"It was my siblings as well, they got the short stick here and there. I grew up with my mum and dad not favouring me, but ... 'here, let's take Steven to this and that'. Now that I'm older I can see that and they've been a big part of that."
Luatua also has a young daughter with his partner.
Hansen has said in an interview that Luatua's representatives didn't communicate with New Zealand Rugby's contracts team as well as they could have, but Luatua said: "as far as I'm aware everything was on the table. They were aware of my situation.
"I feel like my team communicated that aspect. Whether or not that got to the higher ups I don't know. But my understanding is that New Zealand Rugby were aware of the other offers."
Luatua, who has played 63 matches for the Blues, said he wanted to return to the franchise and potentially the All Blacks after his travels. "One of my goals is to try to clock up 100 games for the Blues so somewhere along the line I'll look to head back... whether or not they'll have me that's a different story so we'll see how that goes."