When they don't want to do outdoor activities. Like roller skating derby, rock climbing, bungee jumping, demolition Derby, hike across the desert or climb a mountain.

If people don't do things to put their lives in danger. They are boring to me. I'm a very high energetic always on the go person.

And even in my 50s I still do a lot of these things.

Edit;

So when all they do is sit on cellphone. They are a waste of my time

When all they want to talk about is themselves. I enjoy getting to know about people I like, but not when the conversation is just a one-way street. When it’s like that, our relationship probably isn’t going to be much different.

When all they ever have to talk about is gossip and complaining about other people.

They have victim complex, they are narrow minded , they are obsessed with politics, they think America is the only thing that exists, they brag about money, they live to gossip, they are naive, they post negative repetitive things which becomes suffocating after a while. They give no inspiration or energy to be around or have up in your feed.

A paragraph response to a yes or no question.

If they're the kind of people who are not even willing to try on themselves and give themselves a chance and would rather identify as victim and talk all day long about how they're being victimised. People who fail to take accountability and responsibility for themselves.
These people have no mental space for anyone else.

when they're a kiss ass that tries to be popular/fit in with everyone else; I have no time for people that have no mind of their own...

Those who are self obsessed.
They are into what they like and have no common ground for you to meet them halfway

If I don't respect them, the last thing I want to do is listen to them or interact with them.

I don’t know but I do find interesting people with intellectual curiosity

Fast talkers, Over talkers, Know-it-all's (other than me...) Single interest types.

Having two standards: harshness towards others and generosity toward oneself.

When they ONLY talk about themselves and never act interested when YOU talk.

When they have no personality and are confused by people who do

No manners, always talk about their issues but have no interests in yours or very little or put tidbits out there that are confusing , and leave you in the dark , talking about non events , excessive profanity I’m probably guilt of that …. Basically they have cotton in thei ears when it should be in their mouth… and dishonest!

Lack of imagination

When they are narcissists bragging about themselves. Nothing more boring than that especially if you know them well and know they are building themselves up and not telling everything.

[c=BF0000] I think none is boring
Everyone is different
Everyone is interesting but I don't know why others find me boring
May be it's because they can't relate me[/c]

When they have no opinions of their own. I hated when a woman tried to feel me out or guess my thoughts, leanings, in order to conform to them.

When they are obsessed about something I'm absolutely uninterested in and feel the need to constantly talk about it.

judgemental, narrow minded, unhygienic, narcissistic, arrogant. They bore me quickly.

Not so much the conversation content but if I am there and in person and they smell sour!
I have to leave.

when they dont have anything interesting to say. if they talk in a monotone. no enthusiasm.

I almost never find anyone boring but I often find them as annoying or being an A##hole.

Nothing new to talk about, quiet, and not willing to try new things.

When they show no interest in other people or the world at large.

Unwillingness to try on new experiences. New ways of thinking

Their silence and self talks

About 25 years of marriage. Lol.

They only talk surface, all the time

They have figured out life

Narrow-minded and dramatic

When thay say talk 2 the hand

Someone uninspiring

Wokeism

being straight

i don't know.

When they display the characteristics of a narcissistic sociopath within 4 minutes after first meeting them.