Regardless of how much stronger he was compared to the vast majority of the people he knew, deep down, he was aware of just far the gap was between him and his ultimate goal. This humbling affected Zoro on a deep level, so much so that it seems to have caused him to become much more serious.
According to him, Zoro likes to get lost because of the Sandai Kitetsu sword. After Zoro got the sword back in Loguetown, he often got lost. Even though the sword does not have any curse like Enma, this makes Zoro lose the ability to determine direction. Sandai Kitetsu is one of the lowest grade swords among Meito.
It's entirely possible Mihawk noticed through their duel and training that Zoro suffers from ocular dominance in his left eye. That is to say, the left eye is stronger than the right. As a result, maybe Mihawk scarred the left eye shut and instructed Zoro not to open it until his right eye was trained enough.
Prior to One Piece's timeskip, Zoro's left eye was fully functioning and completely uninjured. Yet when the Straw Hats reunited after their respective adventures, Zoro's left eye was mysteriously scarred shut. Prior to the timeskip, his left eye had been seen glowing when using certain attacks.
How did Zoro lose his left eye? He never lost it. It is a scar over his left eye that has been there after the time skip, and many fans are theorizing on what might have happened to it. For example, Zoro has a hidden power sealed beneath his left eye, and when he opens it, a hidden power is unleashed.
He was asked to defeat the Humandrills on the island and, eventually, train with Mihawk as well. At some point, however, Zoro sustained an injury to his left eye. What exactly happened here remains unknown to date, however, Zoro's left eye has been closed ever since.
Zoro wanted to see if he was worthy of Mihawks little knife necklace thing so he threw it it the air (like his cursed sword) and it slashed his eye which meant he still wasn't worthy to wield that knife.
Many point to Zoro's Asura form as being related to this change. Others base it in real-world vision-strengthening tactics, such as covering up one eye to force another to compensate and become better in depth perception.
After the Timeskip. After the two-year timeskip, Sanji now covers his right eye, shows his left eye, and has grown his hair just slightly longer. He also sports a dark anchor style facial hair, and stubble on his upper lip. Sanji's neck has gotten thicker as well, similar to Luffy and Zoro.
Zoro and Sanji's differing philosophies
At the core of One Piece's most famous quarrel, the eternal bickering of Zoro and Sanji, are two foundationally different philosophies. The reason for this primarily ties into Zoro's backstory, particularly his upbringing in Shimotsuki Village.
The reason is because Zoro understands exactly what Luffy means just by a look or by even Luffy calling his name. Luffy goes to Zoro the most out of anyone on the ship even for the smallest of things. He has proven to understand Luffy the first time when they met each other.
So, for fans who wonder why Zoro stopped laughing, it isn't as simple as merely losing his sense of humor along with his sense of direction. Rather, it was due to Zoro realizing just what his crew needed him to be, as well as what he needed to become, in order to accomplish his own goals.
One of Zoro's most prominent weaknesses is his utter inability to follow directions, resulting in him frequently getting lost. He only became a bounty hunter after leaving Shimotsuki Village because he lost his way while out at sea looking for Mihawk.
Roronoa Zoro (ロロノア・ゾロ, Roronoa Zoro, spelled as "Roronoa Zolo" in some English adaptations), also known as "Pirate Hunter" Zoro (海賊狩りのゾロ, Kaizoku-Gari no Zoro), is a fictional character created by Japanese manga artist Eiichiro Oda who appears in the manga series and media franchise One Piece.
Enma is the strongest sword possessed by Zoro of the Straw Hat Pirates right now. What is Zoro's weakest sword? Sandai Kitetsu has to be the weakest sword Zoro has used until now in the One Piece manga and anime.
Over the years, he has come a long way and become one of the strongest pirates on the seas. Zoro has attained terrific strength, but he does not rely on a Devil Fruit at all.
9 Won't Eat: Roronoa Zoro
Wielding three swords, Zoro possesses immense proficiency in this art and, over the course of time, his Haki has been consistently improving as well. For someone like Zoro, eating a Devil Fruit doesn't make much sense because he doesn't need to depend on one.
It limits his sight and his depth perception in particular, and it would get hair in his open eye whenever the wind blows. You could say its because he's ashamed of his relation to Germa, but if he really cared that much, he would have just shaved the twirly bits off both his eyebrows, like he recommended Duval do.
Mihawk outclassed Zoro when the two fought over Baratie, and even now, he is superior to the straw hat swordsman in terms of skill. On the Sabaody archipelago, Rayleigh fought Kizaru and hit him in battle and even wounded him during the battle.
When he engages someone in combat, Zoro often tests their skill first and, upon getting serious, he then dons the black bandana on his head, which is often an indication of him acknowledging the strength of his enemy.
During this arc, Zoro and Luffy, having lost their memories, confront each other and engage in a fight. It is during this fight that Zoro lands a strong surprise attack on Luffy, slicing his chest and thus giving him the X-shaped scar.
Zoro usually carries three swords with him to perform the three-sword style anytime. So currently, he has the Wado Ichimonji, Kitetsu III, and Enma with him. What is Zoro's weakest sword? Out of the swords he currently owns, the Sandai Kitetsu is the weakest blade in his arsenal.
Fearing its curse, he refused to sell it until Zoro took a liking to Sandai Kitetsu because of its cursed nature. Zoro courageously tested his luck by risking his arm, extending it against Sandai Kitetsu's falling edge, ultimately keeping the sword after his luck prevailed over the curse.