Is ennui an inevitable consequence of eternal life?

Yes; it made me think of this thread too.

In a previous thread about which superpowers you’d like to have, I said the powers of Superman and Immortality. I put a caveat on both in that they could cease at any time if I willed it. You’d hate to get stuck in the middle of a sun with no way to get out of it.

I’d say that if people were able to live forever they should be given the option to opt out of it at will. You could take the choice to end it forever, or fast track things to be reawakened in hundreds or thousands of years, kind of like in ‘City and the Stars’ by Arthur C. Clarke.

I also think a person’s perspective would change. I know myself, I’d have little incentive to work other than to make enough to work on a project that interested me. Then again, I’d probably go to school so I could work in an area of interest. Something that would be very difficult for me to do at this stage of my life. Right now I have to save for retirement unless I’m willing to take the chance of the state looking after me when I get old. If I lived forever I wouldn’t have to worry about it.

Given the numbers of things that people do to make a living, I could pass many lifetimes trying even a small portion of them out. So, you spend a century working, then a decade or two off doing hobbies of some sort or another, after which you go back to school for another decade to learn how to do something else. Before you know it a millennium or two has passed. I can’t imagine being bored by doing only the things I want to when I wanted to do them. What stress would there be if I didn’t get it done today? There’d be many more days after to finish things, to work on this project, to finish that one.

All I know is a billion years is an awful long time.

First of all, is everyone immortal or just a few people? I think that would make a profound difference if you had to deal with generations of constant personal loss vs never having to deal with it ever.
According to Wikipedia, boredom "boredom arises not for a lack of things to do but the inability to latch onto any specific activity. Nothing engages us, despite an often profound desire for engagement.

There appear to be three general types of boredom, all of which involve problems of engagement of attention. These include times when we are prevented from engaging in something, when we are forced to engage in some unwanted activity or when we are simply unable, for no apparent reason, to maintain engagement in any activity or spectacle."

So I’m not sure if being immortal would make you bored. Clearly there would be times in your life when you would be bored, but you would have all the time in the world to try, if not master, any number of hobbies, interests, careers or other activities. Then again, having all the time in the world could be a big demotivator. Much of what we do is driven by a need to find fullfillment or complete a goal in a short amount of time.