In the Star Wars prequels, Jango removes his helmet more or less whenever he's not fighting, happy for Obi-Wan, the people of Kamino, Count Dooku and others to see his (or, indeed, Temuera Morrison's) face.
Bo-Katan, Koska Reeves (Sasha Banks), and, Sabine Wren, who'll make her live-action debut in Ahsoka, among others, have freely shown their faces. From a storytelling perspective, Boba Fett removing his helmet offers The Book of Boba Fett better opportunities to tell compelling stories.
Jango's armor was inherited by his cloned son, Boba Fett, who became a deadly bounty hunter. With Jango's death, his armor passed to Boba. During the Clone Wars, Boba tried to kill Windu with a bomb that he planted inside his father's helmet.
No. Jango's head is not in the helmet when #BobaFett picks it up in #AOTC. If you watch closely, you can see evidence of this with a shadow effect used in the scene.
In Season 2, Din removes his helmet to say goodbye to Grogu after leaving his surrogate son in the care of Luke Skywalker (Mark Hamill). It's a touching moment that proves how much Din loves Grogu, to the point of betraying the Children of the Watch's teachings.
Some Mandalorians, most notably members of Death Watch, held a grudge against the Jedi for their perceived crimes against Mandalore during the Mandalorian-Jedi War. During the Clone Wars, anti-Jedi sentiment further developed in a segment of the galaxy's public opinion.
According to The Way, Mandalorians are not allowed to remove their helmets. If another being sees a Mandalorian warrior without their helmet, they're forbidden from ever donning it again. This rule seems relatively straightforward, if extremely cumbersome, but its enforcement is harsh.
Jango Fett was a Mandalorian. He got the distinctive Beskar steel armor and attached weapons systems the same way every other warrior of the clan did; he earned it. Jango fought in the Mandalorian Civil War as a Mandalorian Commando. He was a foundling, just like Din Djarin long after him.
Boba Fett's armor was a suit of customized Mandalorian armor worn by Boba Fett, a cloned human bounty hunter. The armor once belonged to Jango Fett, a Mandalorian foundling. After Jango's death, the armor fell into Boba's possession.
The very important Luke Skywalker connection
Boba Fett was actually the one who let Darth Vader know that his son was alive and that the Skywalker bloodline lived on outside of himself.
After the death of Jango Fett, Aurra trained Boba Fett as a bounty hunter, teaching him the skills -- and the ruthlessness -- that he would need in pursuing his deadly profession.
The most prominent color of Boba Fett's armor, the color green in Mandalorian culture symbolizes one's value of duty. Being a bounty hunter, Boba Fett has a distinct responsibility to himself and his employers.
One thing you have to give Boba Fett credit for, after all he's been through, his time in the Sarlacc and the Tusken he's managed to keep his teeth white and shiny. I think he has a very good dentist.
Burned By The Digestive Enzymes Of The Sarlacc
Boba Fett ended up inside Sarlacc's stomach [1]. While being digested alive and close to being breathless, Boba Fett was exposed to the digestive enzymes of the giant intergalactic monster. Due to this, Boba Fett's skin was burned and ended up scarred.
By this logic, it's likely that Mandalorians are also able to remove their helmets for sleep as well. Since Mando felt comfortable enough to unburden himself of his headgear when eating, there's a good chance that he is fine with leaving it off when he is isolated from others while taking a snooze.
This bounty hunter chooses to sleep in a bacta tank to heal the injuries he got from the Sarlacc and Tusken Raiders, who later befriended him [1]. This sealed water bath relieves his body, and the tank helps ease the pain of his internal and external wounds.
Beskar, also known as Mandalorian iron or Mandalorian steel, was an alloy that was used in Mandalorian armor and was notable for its high tolerance to extreme forms of damage. In its purest forms, the metal was durable enough to withstand a direct blaster shot and could repel lightsaber strikes.
In The Mandalorian, the armor that he wears was passed down by his father, and he considers it his birthright, but not something he has necessarily earned in the eyes of the Mandalorian. As a result, Boba Fett is not considered a true Mandalorian.
4 Durasteel Armor
The implementation of this material in his armor allowed Vader to survive almost any type of gunfire aimed in his direction. Though Jango Fett's armor was later altered to consist primarily of Beskar, there is no denying the power in a Durasteel suit.
In contrast, Din Djarin's armor was made from pure beskar, earned through the bounty on Grogu. This made Djarin's armor rare and even more durable than normal Mandalorian armor, allowing it to stay shiny and undamaged even when he walked into a barrage of blaster fire.
Also known as Mandalorian steel, beskar is a rare alloy best known for being one of the few substances that a lightsaber can't break through.
How do Mandalorians shower? Bounty hunting is a dirty business, and it's unlikely that basic hygiene is off the table for the Mandalorian, tradition notwithstanding. While this hasn't been confirmed outright, we can also presume that Mandalorians also shower or bathe in private, sans helmet.
Is Grogu Yoda? According to the events of "The Mandalorian" so far, Grogu and Yoda are not the same character. They are simply from the same species. The name of this species has never been revealed since "Star Wars" creator George Lucas wanted to give Yoda a sense of mystery.
Din Djarin is force sensitive and will become Mandalore the Redeemer : r/StarWarsTheories.