I'm in no position to comment about fan behaviour but I can say a tiny something about nerves...
How do you deal with nerves? One way is undoubtedly to voice them. Talk about how on edge you are, vocalise it with moans, really transmit your nervous energy...
Another way is to try and transfer those nerves. I have been on stage a couple of times - not to big audiences by any means, but maybe 50-60 people, definitely enough to feel nervous - and one thing that really does help is to lose yourself in performance. Like actually take the nervous energy and throw it into the song, into the run, into the fight, whatever...
Energy can't be created or destroyed. For sure it's no use telling people not to be nervous, that isn't how life works. But energy can be transferred. So it's absolutely possible to turn that nervous energy into some other energy. Anger is often the (understandable, natural and evolutionarily useful) alternative, but any emotion works, any performance works, any action.
Mane is a great example of this. The more emotional the game state gets - especially negatively - the more it seems to wind him up to run, to fight, to tackle, to try and score. It's not that he doesn't get nervous, it's that he's very good at transferring those nerves into useful energy. He's a very emotional player but also, I think, very able to use those emotions usefully on the pitch. Compare that to Robertson last night, a very passionate player who perhaps let his emotions (disappointment? shame?) get the better of him last night in trying to take too much on himself...
