Nole has always been like this, up and down, more up than down to be honest, except his freak season. He simply has his off days. However you always can count on those days he will fight all his all. That's what I like about him, he can't expect to play at goat level every match or even half the matches, so then other factors count. To be nº 1 you need more than talent and skill. You need positivity, mental strenght, uber confidence, fight, spirit, patience... he has all that in spades. He will be fine.