Cowboy is obviously dealing with his anxiety issues with constant action, whether it's fighting or some of his multiple hobbies. If he's left alone with nothing to do, he'd go crazy which is probably related to his internal unresolved, childhood issues. He's trying to get out of his head with running from one challenge to another trying to escape from himself.
If there was a long build up like Aldo-McGregor world tour he'd crumble under pressure during the anticipation, while Conor is exact opposite, he thrives under pressure.
Conor would come in the fight strong, while Cowboy needs some time to relax and get going so It'd be a very short and easy fight for McGregor.