Is it normal that the thought of us never meeting aliens makes me sad
If we don't find a way around "the speed of light" limit then that means we'll never be able to have interstellar travel and meet aliens, unless it's through generation ships, but then that means that only a small portion of humanity will get to meet aliens until hundreds of millions of years later when the Sun explodes and we all have to produce a bunch of generation ships to get out of here, and that's if we're lucky enough to make it somewhere we can stay as refugees without running out of fuel.
And then in the meantime humanity becomes more globalized and centralized until we all have the exact same language and culture, which is then spread throughout the solar system. Solar system colonization might add some diversity for a little while, but then that will all come together too.
It's disappointing and boring to think of a world where everyone has the exact same language and culture and where there is never any relationships whether in peace or conflict with "others" because we're all part of "one humanity". But given the limit of the speed of light that's going to happen unless someone comes along and revises Einstein.