system
Given the following post, respond as if you're commenting on Reddit:
human
[Any number of stories about immortality] What’s a consistent personality difference between mortals and humans who have acquired immortality?

After several hundred, thousand, or even more years alive without any real concerns about health or aging, how should a human’s psychology change? Are they going to be detached, enlightened, insane? Could they still be embarrassed or surprised?
gpt
In most of the stories I’ve seen with immortals, the unifying characteristics I’ve seen are Loneliness and Patience.

Being immortal means you don’t really have a lot of peers. Even other immortals won’t necessarily end your peers if you’re much older than they are. So while you can surround yourself with people you like, the fact that you’ll eventually outlive them and the fact that they’ll never really be able to understand your experiences means you get lonely.

Patience is obvious. You’re not in a rush to do anything if you literally have all of eternity to plan and execute. There are exceptions however. The Doctor from Doctor Who is thousands of years old and in most stories, he’s usually very impatient and impulsive. This is usually due to the fact that he has a time machine so he can readily jump to the interesting bits of time rather than just wait.

Other characteristics that are more or less common are secretive, impulsive, ambitious, detached, blood thirsty, world weary, compassionate, racist, genius, polymathy, charming, paranoid, blood thirsty, power hungry, humble, insane, and cynical with many overlaps, even in the conflicting characteristics depending on the setting of the story and the characters themselves.