Navi understood this.
She was the watcher of the watchman - giving him sound advice preceded by her characteristic "Hey! Look! Listen! Watch out!" – her sharp, piercing voice breaking through Link's stupor and getting him off his obsessive compulsive, one track mind. She would help him and be there for him and tell him what he needed to do and, most importantly, when he needed to stop.
She would hold him and his indomitable will to explore and to help and to do things in check – his balance, his guide, his moral compass.
Like when he would hang around Lon Lon Ranch for days at a time, pacing to and fro between the rough dirt track and the cobblestone wall from sunup to sundown – at which point he would quickly retreat to Kakariko village. He would be muttering under his breath, closing his eyes and trying a variety of poses and mannerisms of speech -trying to pluck up the courage to go in and say hi to that redheaded girl again – Navi would tell him that Zelda needed him to do something or that he hadn't talked to Saria in a while and off he would go to more important and less stressful things.
Like when he hung around the Kakariko Village graveyard – patrolling the headstones – lightly brushing off moss and mould where he could and rearranging and bringing fresh flowers where he couldn't – Navi would comment that Dampe, the cheerful gravekeeper, already had that job and that Link needed to go and help Anju with the cuccoos again.
Like when he wouldn't – couldn't – abandon the corpse of the soldier who had valiantly given his life to protect Princess Zelda from the clutches of the King of Thieves, Ganondorf – Navi would gently tug on his green cap as he tried feeding the dead man Lon-Lon milk, giving him the Ocarina of Time or the three sacred gemstones and doing anything, everything, he could that was medically, humanly and spiritually possible to save him.
