What do "staring down the barrel of my own mortality" and "feel sidelined" mean?
Hello. Could anyone please explain two phrases from the TV series "Russian Doll" episode 1. What does "staring down the barrel of my own mortality" mean? And what does "feel sidelined" mean? I think I kind of understand them but I'm not really sure.

Maxine: Are you having fun?
Nadia: Fun is for suckers, Max. Two minutes ago, I turned 36. Staring down the barrel of my own mortality always beats fun.
Maxine: Don't be morbid. This is your party, and I'm making you a birthday chicken.

A few minutes later, a man says this (it's not related to the dialogue above):
So when people say working class, what they really mean is people who can't afford to go to college. So these people, they feel sidelined by the American dream, right? So they resort to xenophobia and the bigotry, which the right stokes with pundit bullying, which is why we're in the situation we're in now.

Question

What do "staring down the barrel of my own mortality" and "feel sidelined" mean?
Hello. Could anyone please explain two phrases from the TV series "Russian Doll" episode 1. What does "staring down the barrel of my own mortality" mean? And what does "feel sidelined" mean? I think I kind of understand them but I'm not really sure.

Maxine: Are you having fun?
Nadia: Fun is for suckers, Max. Two minutes ago, I turned 36. Staring down the barrel of my own mortality always beats fun.
Maxine: Don't be morbid. This is your party, and I'm making you a birthday chicken.

A few minutes later, a man says this (it's not related to the dialogue above):
So when people say working class, what they really mean is people who can't afford to go to college. So these people, they feel sidelined by the American dream, right? So they resort to xenophobia and the bigotry, which the right stokes with pundit bullying, which is why we're in the situation we're in now.

Answer

A gun metaphor and a sports metaphor: That's American English for you!

The "barrel" in the first one is the barrel of a gun. When you are facing a difficult situation, you can think of that situation as being a gun pointed at you. And here the "difficult situation" is turning 36, which reminds her of her mortality. Actually, it's good writing because mortality is a barrel we all have to stare down.

As for "sideline", like I said above it comes from sports. Basically most sports have what is called "in bounds" and "out of bounds" - basically where you can play/where you can't. The "sideline" is the actual limit that is painted on the field/court, and "the sidelines" mean outside of the game. So if you are sidelined, you are pushed out of bounds. In real life that means you can't really participate in the American Dream because outside forces have pushed you out the game. Hope that helps.

Answer

To ‘ stare down the barrel’ is a truncated (shortened) version - often concluded with ‘of a gun’. It’s a reference to suicidal thought. A person considering self slaughter by using a barrelled weapon such as a pistol or a rifle might look down the barrel in contemplation. Hence Maxine saying ‘Don’t be morbid’ - stop talking about death.

To ‘be sidelined’
The ‘sidelines’ of a football field run along the sides of the field. Off a player is sent off, or prevented from playing because he is not needed he/she is sidelined. Unwanted. Superfluous. Unnecessary. This isn’t associated with absence of rejection. No one likes to be sidelined:(

Answer

"staring down the barrel" is looking into the end of a gun which means that death could happen immediately.

"feel sidelined" refers to a player in a sport that is not participating in the game.  He is on the bench or the "sideline" of the field  or pitch waiting for his turn to play.