if you can forget why you ever loved your family, couldn't you also forget the things you've done and seen and approach them with new wonder and never get bored?

that's quite besides the point though. i feel like you're focusing too much on the 'forever' aspect. obviously, if you really feel like you've 100%ed reality and want to, you can choose to die, but i don't think you'd be likely to reach that point because the universe is not a static place. the world is constantly changing, so by the time you'd seen 'everything' that same everything would be different.

also, i've found that relationships can certainly wither even within a normal human lifespan, if not maintained, but if they are, you'll be reminded of why you love each other regularly enough to not forget.