Let’s say we left one single very smart guy (not necessarily with the knowledge: they may be able to understand hard stuff when taught it, but not know it already) alone on a copy of the earth. That person is also immortal. Could that person, by themselves, gain back all knowledge, maybe also experimental, or even surpass that is already available to us right now, before the planet gets inevitably engulfed by a sun turning red giant?
This is an interesting take based on the quality of years. But unless the task becomes impossible to, and not just more arduous, the answer should still be yes.
Whether the person enjoys life or not is another question.
Haha. I think we threw that question out when we assumed immortality.