You've got a good point. Maybe if a human baby was raised in an alien
culture, perhaps they could learn that culture.
    But maybe I should have said, could a human understand aliens?
    Aliens would have a different evolutionary background. They might have
completely different brains and bodies. It might be difficult or impossible
to feel as they do, or think as they do.
  Given enough time, they might be so evolved that they might function in
ahigher dimension. And this is just a modern human concept.
They might not even have bodies as we know it. And our sense of personal
identity is closely related to our bodies.
  Say they are just 100 million years ahead of us, they might be
incomprehensible - maybe even unperceivable.
  Might even be true if they are only 10,000 - or maybe just 1000 - years
ahead of us, assuming a logarithmic evolution.
  Even if their brains were just a little bit more evolved than ours - say,
whatever comes after a cerebal cortex - we probably couldn't understand
them, or even know how to understand them
  So why even try - don't we have more significant things to do?