To eat, for example (no, they don't absorb nutrients through a tube hidden in their armor). Mando actually did so in the episode, though his head was still hidden from viewers. Mandalorians are just not allowed to take off their helmet in front of someone else. No other being can see their face.
And while there are many rules guiding Mandalorians and showing them “the Way,” the most iconic aspect of their culture is related to their armor. That's because, as Season 1 of The Mandalorian underlines, true Mandalorians are forbidden from ever taking their helmets in front of others.
This would put Gideon is a very unique position - the only living character in The Mandalorian to have seen Din Djarin's face, and have a vested interest in using that information to his advantage.
Can mandalorians who belong to the children take their helmets off to (insert action)? Yes. They can take their helmets off to eat, cut their hair, sleep, etc. the rule is that they cannot remove their helmet in front of another person.
Mandalorians do marry and can marry anyone they want.
While it's not confirmed whether Mandalorians leave off their helmets when bathing and grooming themselves, it's likely that they do so.
Every since the series debuted and confirmed that Mandalorians never remove their helmets, I've been wondering how they get any sort of nutrition. The answer, it turns out, is neither “through a secret hole somewhere” or “they exist on a liquid diet” but rather…they just eat in private.
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.
Mandalorians are celibate. Like their parents, and their grandparents before them.
We've already established that we ship a relationship between Din Djarin and Bo-Katan Kryze, so we'll be paying close attention to how the two interact as the season heads for the home stretch.
Even under the Draconian rules of Death Watch, Mandalorians can remove their helmets when they're alone. For practical purposes, Djarin is free to put the headgear aside whenever he's by himself.
Then, when Djarin and Mayfeld are stopped by a commanding officer, he is ordered to remove his helmet. He hesitates, but his ultimate goal is to save Grogu and he can't risk failing the mission by refusing to obey the commander's orders. As a result, he removes the helmet.
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.
Most prominently, the female helmets resemble the designs of Spartan helmets, with rounded eye designs, where the men have the simpler visor. The different styles help viewers distinguish men from women, and helps show the make-up of the Mandalorian forces.
An athletic and agile Twi'lek, Xi'an is the bladed weapons expert of a gang of criminals working with the Mandalorian.
Mandalorians' weddings are simple, and they can marry anyone. If they wed a non-Mandalorian, their spouse needs to vow to live by the ways of Mandalorian society to join effectively. Queer couples were allowed to marry as well.
Though many residents of the galaxy viewed Mandallian Narcolethe as the Mandalorians' most prominent alcoholic beverage, a large number of Mandalorians preferred ne'tra gal to the Mandallian liquor.
Over time, a gentle headbutt consisting of a tapping of helmets together at the forehead, came to be a stand-in gesture for a kiss among Mandalorians adorned in full armor. The practice led to the development of the slang term "Keldabe kiss," derived from the name of Mandalore's capital city.
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.
But, it appears something changed between the events of Revenge of the Sith and the end of the original series. During this time, the Mandalorians appear to have suffered some sort of devastating loss to their clans, forcing them into hiding, and leading them to keep their helmets on at all times.
It's a space toilet. It's called a "vac tube" and it looks just like a round, tilted hole in the side of the titular character's ship, like an advanced version of an airplane toilet.
Mandalorian warriors are some of the biggest badasses in the universe, and they don't gain that kind of reputation by sleeping in late. Therefore, it's safe to assume that The Mandalorian sleeps with one eye open, and wakes before his enemies.
According to the ancient way of Mandalore, a Mandalorian cannot remove his/her helmet in front of another living being. If he/she does that, then they will no longer be a Mandalorian. That's why Din agreed to take his helmet off in front of IG-11 in season 1, as he was just a droid.