While eternal life seems fun at first as you would be able to see civilizations rise and fall, does the downsides of immortality out way the upsides to it?
If you think about it, what could be worse than eternal life? This is because eternal life is not eternal youth, you would still grow old and face the challenges of growing old. While medicines are getting better and allowing people to live longer, our current medicine would not be prepared for someone aging forever. The medicines would eventually become experimental as medicine would not be able to keep up with you. This is assuming that you were randomly gifted or cursed with immortality and not given some sort of Mire repair kit, like in Doctor who, that keeps you at the age you were when you were given it and keeps you healthy.
Another flaw of immortality is that you would eventually run out of people to talk to as humans would either become extinct or carry on evolving to the point of humans being unable to communicate the same way as we do now. You would be considered practically a caveman a couple of hundred thousand years from now and would be something that would be studied as you would no longer be able to communicate with others. There would be a point in your life when you stop being classified as a human, and humans in the future would see you as the last of your species that takes a long time to die rather than you being an immortal human born in their version of ancient history like the early Romans are to us.
On the topic of the Romans, we view them as ancient history. Books that they wrote are considered classical, buildings that they built are considered ancient monuments. The fall of the Romans empire occurred in 1455 AD, around 600 years ago. In terms of our life spans that is a long time ago, and our perception of time is warped now, but imagine what an immortal would see 600 years. As an immortal people would expect you to be at all the important events in history so that you be an eye witness but you could be have been on the other side of the world.. Being an immortal does not mean you get the ability to time travel until they invent time travel in the future, if they invent time travel.
Being immortal means that you are simply immortal you are not a time traveller or planet explorer. You would still have to an ordinary job to live and the qualifications and expectations for jobs are getting. While you have experience in your job you wouldn't be able to change it to be your dream job because you would be stuck being unable to change because the expectation would be too high. While you know basic maths and science, you will struggle remembering new advances in science, just look at people born before smart phones and how much they struggle to understand the new technology. You would eventually get to the point where you stop trying to learn things as you won't understand the basics of it.