It's hard for humans to conceptualize eternity, so don't think of it in those terms. If I could live in my current body for 1000 years, I'd still never get around to most of my backlog of things I'd like to do.
Boredom is mostly caused by lack of purpose IMO. As long as there is something to learn, something to explore, something to achieve, something new or pleasurable to experience, boredom is the last thing I'd worry about.