Eddie Bravo is a third degree jiu-jitsu black belt who runs the famous 10th Planet Jiu-Jitsu gyms in locations all across North America. Some of his pupils include Ronda Rousey, Chuck Liddell, and Joe Rogan, who's podcast he appears on from time to time to talk jiu-jitsu and MMA in general.
It was on the most recent Joe Rogan podcast that Bravo told an interesting anecdote on Conor McGregor and his mentality in terms of learning jiu-jitsu. It's understandable that most UFC fighters don't want to walk into a gym and immediately ask to roll with the best grapplers there, as they have an ego and a public image that they wish to protect, but none of that matters to The Notorious Conor McGregor, and that's why Bravo think's he can become a top-level jiu-jitsu practitioner.
A glowing review of Conor's mentality.
Say what you want about the manner in which he hypes up his fights, but nobody can deny his dedication to the sport he loves.