Many people get human intelligence wrong. They think we have a limit. Or that highly evolved aliens will likely be so much smarter than us that we will be unable to understand them. Us to them would be like chimpanzees to us. But people who make this kind of analogy totally underestimate human intelligence, or the uniqueness of human intelligence compared to chimpanzees and every other species.
A much more apt comparison would be that a highly advanced intelligent alien species would be like Albert Einstein compared to a 4-year-old human. Einstein will be vastly, incomprehensibly more intelligent than any child. A 4-year-old will not understand anything about physics or relativity, but that child can understand physics and relativity and anything Einstein understands, given time.
Human intelligence is unique because a human has the capacity to understand anything. There is nothing that a super-intelligent alien or future humans could understand that we, in principle, cannot. It may take time and effort to learn it, but eventually we can understand anything. That's what makes humans different than other species, that's what makes us "special."