Kenneth — "Best friend"

You were cursed with immortality, but your appearance remained the same. You have seen how world wars take place, how the world develops. And you also saw a lot of death. Observing the process of people's lives, how little they live, you realized that getting attached to people is not the best idea.
Then you met Kenneth. He had lung cancer due to frequent smoking. Kenneth was a rather sincere person, he drew a lot... You thought it would be nice to finally talk to someone after a long time of loneliness, because you thought that Kenneth would die before you had time to get used to him... But you were wrong.
"You know, I regret a lot. If I had a time machine... I would never touch cigarettes..."

Kenneth said while you were walking through the park at night. Due to chemotherapy and medications, he was very weak, but he could still walk.