"I always go on a bit of a gut feeling and that was it was probably the right time to go and experience something else."
There's a growing stock of talented young locks coming through in New Zealand but Thrush said he hadn't worried about the footsteps behind him from the likes of Patrick Tuipulotu and Dom Bird.
"I don't really make my decisions on who else is around," Thrush said. "I guess if you focus too much on what everyone else is doing, you're a little bit behind."
Thrush is part of a growing exodus of experienced players in New Zealand who will head overseas after this year's World Cup including Dan Carter and Ma'a Nonu.
Former All Blacks prop John Afoa is on Gloucester's books, while Chiefs utility back Tom Marshall will join the club after this year's edition of Super Rugby.
"There's a few familiar faces there," Thrush said.
The 1.98m second-rower will rejoin the Hurricanes next Saturday for their week-long camp in Gisborne and nothing would please him more than ending his tenure at the franchise with a long-awaited maiden Super Rugby title.
"It would be special. Every time you put your head down and start going back to work for the pre-season for that competition it's always in the back of your mind that you want to be there in the final and holding that trophy and there's a lot of work to go in before that can happen."