The Lions are celebrating back-to-back premierships after Saturday's 47-point grand final win over Geelong, with Fagan admitting this felt better than last year's triumph against Sydney.
Fagan added on Monday that the two premierships meant he no longer felt like a coaching impostor, given he had never played in the AFL and considering his unique progression from Tasmanian football through to the Lions.
Asked about Brisbane's prospects of claiming the latest flag three-peat, Fagan said his players' mindset remained the most important factor.
"We talked about again, after (Saturday's) game, that the key to us having a good year this year was we didn't get carried away with ourselves last year after we won the premiership," Fagan told AFL360.
"We got some confidence from it, but we stayed humble as a group. I didn't see anyone develop a sense of entitlement at all, which I think is very important.
"As long as we stay grounded, we can obviously challenge again next year. If we can do that, we're a chance to be successful again next year, but that's the $64 question."
Fagan revealed he had received a "magnifcent" text from AFL great Neale Daniher, who brought him from Tasmania to work at Melbourne in the late '90s.
"It did mean a lot to me and it probably referenced a little bit that idea that maybe I didn't feel like I belonged, but hopefully I do now," Fagan said.
"It was a tremendously courageous decision by Neale and I will never be able to thank him enough.
"There were times, even up until last year when we won the flag, I felt maybe there was a little bit of impostor syndrome. I feel (now) like maybe I do belong in the coaching ranks."
Fagan is now minding the premiership cup and it already looks worse for wear.
"I brought it home tonight and (his wife) Ursula had a look at it and said, 'There's a dent in that cup'. Sure enough, there is," Fagan said.
"We might have to get a few little repairs done. Or maybe just leave it there, as a part of history."
Fagan said he enjoyed this flag more than last year.
"I just think winning two in a row is very, very hard to do," he said.
"I just feel like we've had to go through a fair bit more this year than last year.
"I think it's better than last year. There's a lot of satisfaction around it."
Fagan spoke again about the risk of playing Lachie Neale, given his calf injury at the start of the finals.
The coach was vindicated when he brought on Neale as ther substitute at halftime and the star Lion helped them kick clear.
"I felt that if he started and ran out of gas, that might be a bit of a spirit killer for the boys," Fagan said.
"But ... if he could come on around about halftime and do what he did, it would be an enormous spirit lifter for us."